c++ const

Help with c++ Huffman BTree!?

2009-07-14T20:15:00.000-07:00

Hey guys with the folowing protoype and function,

I am getting this error, which says...

In function `void getHuffmangetHuffman(BTree*, std::string%26amp;, std::string*)':

error: invalid initialization of non-const reference of type 'std::string%26amp;'

from a temporary of type 'std::basic_string%26lt;char, std::char_traits%26lt;char%26gt;,

std::allocator%26lt;char%26gt; %26gt;'

can someone please help me out......

here is my code below!

void getHuffman(BTree* node, string%26amp; s, string sa[]);

void getHuffmangetHuffman(BTree* node, string%26amp; s,string sa[])

{

if (node != NULL)

{

if (node-%26gt;getLeftChild() == NULL %26amp;%26amp; node-%26gt;getRightChild() ==

NULL)

{

char buf[2];

buf[0] = (char)node-%26gt;getLetter();

buf[1] = 0;

string s2 = buf;

sa[node-%26gt;getLetter() - 'a'] = s2 + " = " + s;

}

getHuffman(node-%26gt;getLeftChild(), s + "1",sa);

getHuffman(node-%26gt;getRightChild(), s + "0",sa);

}

}

Help with c++ Huffman BTree!?
The second parameter of getHuffman is a parameter of type std::string%26amp;. Reference parameters need need to use actual variables in the function call. If you use a literal instead, it'll complain.

For example:

myFunction(int %26amp;nValue);

you can call it as myFunction(nX);

but not myFunction(5);

or even myFunction(nX+1);

Because 5 does not have an address, so %26amp;nValue can not be set to anything. When this happens, the compiler normally puts 5 in a temporary variable and passes the temp variable to the function instead. Same with nX+1.

You have two options:

1) make the std::string %26amp; parameter a const std::string %26amp; instead.

2) When you call the function, pass it an actual variable instead of an rvalue.

land survey

Help on c++?

2009-07-14T20:14:00.002-07:00

I wrote a program that compute %26amp; print the Area of triangle :

#include%26lt;iostream.h%26gt;

main( )

{

const 1/2;

int b,h;

cout%26lt;%26lt;"enter b,h"%26lt;%26lt;endl;

cin%26gt;%26gt;b;

cin%26gt;%26gt;h;

cout%26lt;%26lt;"Area of Triangle="%26lt;%26lt;1/2*b*h;

}

please can any one tell me what's wrong with it .

Help on c++?
1) Remove const 1/2

2) Write b*h*1/2 instead of 1/2*b*h while printing

Your program will run

The MAIN REASON your program isn't giving right answer is you are printing 1/2*b*h. As the compiler reads from left to right and as the priority of '/' and '*' is equal, so it is taking this expression as 1/(2*b*h).

As you haven't mentioned any data type for the answer, compiler is treating it as an integer output. As 2*b*h becomes a large value, 1/(2*b*h) becomes zero (0). So your output is 0.
Reply:First remove const 1/2

It doesnt make sense

Now... since u are using 1/2.. it is a floating point value.

So just add this statement:

float area = 0.5 * b * h;

cout %26lt;%26lt; "Area of Triangle = " %26lt;%26lt; area;

Thats it ;)
Reply:It will give you error at

const 1/2

Sicne C++ does not allow "/" operator in the declaration of Const. If at all you are interested in so, try to use

() in the const declaration.

But I dont see any other error apart from this in the above code.

Any decent c++ programmers out there to translate this code?

2009-07-14T20:14:00.001-07:00

here is doom source code for a file called d_items. Need to know what it means. Is the variables = to a graphic or animation image? Notice upstate, downstate etc, are these animations of the character shooting the gun?

static const char

rcsid[] = "$Id:$";

// We are referring to sprite numbers.

#include "info.h"

#ifdef __GNUG__

#pragma implementation "d_items.h"

#endif

#include "d_items.h"

// PSPRITE ACTIONS for waepons.

// This struct controls the weapon animations.

//

// Each entry is:

// ammo/amunition type

// upstate

// downstate

// readystate

// atkstate, i.e. attack/fire/hit frame

// flashstate, muzzle flash

//

weaponinfo_t weaponinfo[NUMWEAPONS] =

{

{

// fist

am_noammo,

S_PUNCHUP,

S_PUNCHDOWN,

S_PUNCH,

S_PUNCH1,

S_NULL

},

{

// pistol

am_clip,

S_PISTOLUP,

S_PISTOLDOWN,

S_PISTOL,

S_PISTOL1,

S_PISTOLFLASH

},

{

// shotgun

am_shell,

S_SGUNUP,

S_SGUNDOWN,

S_SGUN,

S_SGUN1,

S_SGUNFLASH1

}

Any decent c++ programmers out there to translate this code?
There is no actual code here, it does nothing. These are purely structures containing definitions. Just as you would define a variable. It doesn't do anything until you reference it again and do something with it.
Reply:It's kinda chopped off, but what it looks like to me is a set of enumerations that define the state of a weapon animation. Without more of the code, I can't tell you if this is related to graphics or animations. My guess is that it describes the entire state of a weapon at a given point in time.
Reply:can't really tell by the code you posted. It's standard coding convention that those ALL_UPPERCASE variables are constants they never get changed. S_SGUN represents the same thing in this function as it will in any other function.

Judging by the comments about the upstate and downstate, it sounds like these are arrays holding the address or something similar to the animation code. They might be pointers to it.
Reply:This code is purely definitions, it does nothing. The images are stored somewhere else, probably in an external file.

REctangle code C++ 2005 express?

2009-07-14T20:14:00.000-07:00

Im having a hard time, can some one help me with this program??? This is my assignment, im lost

Write a program that displays a rectangle of given the length (an integer size less

than or equal to 21) and the width (an integer less than or equal to 79). Your

program should accept as input from the keyboard the character used to form the

rectangle, and the two values for the length and width of the rectangle.

Out of range input values should result in an informative error message.

Your program should process only one input case, legal or not. Termination occurs

after either the error message is printed or the diamond is drawn.

It is necessary that the program be written using loops.

Sample runs:

Rectangle drawing program

Enter the character, and length and width (eg. x 7):A 7 12

AAAAAAAAAAAA

A A

A A

A A

A A

A A

AAAAAAAAAAAA

Rectangle drawing program

Enter the character, and length and width (eg. x 7):R 3 5

RRRRR

R R

RRRRR

Rectangle drawing program

Enter the character, and length and width (eg. x 7):A 27 32

You have entered an illegal value for the length. It must be between 1 and 21.

You should use a named constant (const) to define and refer to the box size limits.

This will make it easy to modify the program at a later date if the size restriction is

changed. Write a class called Rectangle. Have the appropriate data members for

that class. Also have a constructor and a function to output the rectangle.

REctangle code C++ 2005 express?
So you need to have 2 functions, one for the header and footer block, and the other for the middle pieces. Then using math figure out how many times to do it.

psuedo code:

gets(userinput);

for ( int i = 0; i %26lt; userinput[2]; i++ )

{

int length = userinput[4];

if (userinput[2] == i || i == 0 )

drawFullCharacterRowOf ( userinput[0], length );

else

drawPartialCharacterRowOf( userinput[0] );

}

void drawFullCharacterRowOf ( char val, int length)

{

for ( int i = 0; i %26lt; length; i++ )

cout %26lt;%26lt; val %26lt;%26lt; endl;

}

This is extremely pseudo code, but you see the point I would imagine.
Reply:// TestCPPConsole.cpp : Defines the entry point for the console application.

//

#include "stdafx.h"

#define MAX_LENGTH 21

#define MAX_WIDTH 79

class Rectangle

{

private:

char m_cUseThisChar;

int m_iHeight;

int m_iWidth;

public:

Rectangle( char cUseThisChar, int iHeight, int iWidth )

{

m_cUseThisChar = cUseThisChar;

m_iHeight = iHeight;

m_iWidth = iWidth;

};

void DrawRectangle( char * szRectangle )

{

char * szTemp = ( char * ) malloc( ( m_iWidth + 2 ) * sizeof( char ) );

try

{

szRectangle[ 0 ] = 0;

memset( szTemp, 0, m_iWidth + 2 );

memset( szTemp, m_cUseThisChar, m_iWidth );

szTemp[ m_iWidth ] = '\n';

for( int iCnt = 1; iCnt %26lt;= m_iHeight; iCnt++ )

strcat( szRectangle, szTemp );

}

catch(...)

{

strcpy( szRectangle, "Error" );

}

if( szTemp != NULL )

{

free( szTemp );

szTemp = NULL;

}

};

};

int _tmain(int argc, _TCHAR* argv[])

{

char cUseThisChar;

int iHeight, iWidth;

printf( "Enter the character, and length and width (eg. x %d %d) ):\n", MAX_LENGTH, MAX_WIDTH );

scanf( "%c %d %d", %26amp;cUseThisChar, %26amp;iHeight, %26amp;iWidth );

if( iHeight %26gt; MAX_LENGTH )

{

printf( "You have entered an illegal value for the length. It must be between 1 and %d.", MAX_LENGTH );

getch();

return 1;

}

if( iWidth %26gt; MAX_WIDTH )

{

printf( "You have entered an illegal value for the width. It must be between 1 and %d.", MAX_WIDTH );

getch();

return 1;

}

Rectangle rect( cUseThisChar, iHeight, iWidth );

char * szBuffer = ( char * ) malloc( ( ( ( iWidth + 2 ) * iHeight ) + 10 ) * sizeof( char ) );

rect.DrawRectangle( szBuffer );

printf( szBuffer );

free( szBuffer );

szBuffer = NULL;

getch();

return 0;

}

======================================...

Disclaimers:

1. Content of stdafx.h file is:

//------------------------------------...

#pragma once

#define WIN32_LEAN_AND_MEAN

#include %26lt;stdio.h%26gt;

#include %26lt;stdlib.h%26gt;

#include %26lt;string.h%26gt;

#include %26lt;string.h%26gt;

#include %26lt;tchar.h%26gt;

#include %26lt;conio.h%26gt;

//------------------------------------...

2. Error handling must be improved

3. Due to deprecation, functions like getch(), strcpy() etc will get warnings. Use other library methods if you are picky.

Doubt in c program?

2009-07-14T20:13:00.003-07:00

volatile constant. this a a datatype right?? eg. const int n=1 means the value of n is going to b constant for the whole program. ant volatile just opposite.but can these exist like i mentioned above???

help if yes means how??

Doubt in c program?
first of all volatile is a C++ key word and its not for what u said..

see Wikipedia:

http://en.wikipedia.org/wiki/Volatile_va...
Reply:Welcome the famous old question. volatile and const are not mutually exclusive to each other. That is to say, these keywords can be used together to qualify a type. Both fall under the 'type qualifier' category of keywords.

const %26lt;type%26gt; var; means var is read only type for the user. the user(in this case, programmer) may not edit a const type.

volatile %26lt;type var; means that everytime something non-trivial needs to be done with the var's value, it has to be read in at that point. Its value may change in unpredictable ways thanks to 'interrupts'(%26lt;--note: this is the keyword here).

volatile const %26lt;type%26gt; var; means, var's value can change in unpredictable ways thanks to 'interrupts' but the user(programmer, in this case) may not change it by hand.

wondering where this kind of thing would be used? look at some (Linux)OS or device drivers code. they use this kind of declarations in many places.
Reply:Yes.the volatile constant may exist given that there is a separate declaration of the number else where in the program.The local scope is of most priority,more than the public and the private scope.So when decl as a constant in public or private and when in the local it is re-declared.,these r caled volatile constant

To declare a costant:

const var_name = var_value;

to decl volatile const

data_type const var_name= var_value;

survey software

I have c++ problem here is the function and its error how can I change my function?

2009-07-14T20:13:00.002-07:00

void codfile(int *a,int n,int codlength)

{

const int memory=n*codlength/8;

int finalCod [memory]={0};

int k=0,fptr=0,cptr=0;

for(int i=0;i%26lt;n;i++)

{

int temp=a[i];

while(cptr%26lt;codlength)

{

if(fptr==8){ fptr=0;

k++;

}

finalCod [k]=finalCod[k] | temp/2;

finalCod[k]%26gt;%26gt;1;

temp/=2;

cptr++;

fptr++;

}

error in line 4: constant expression required

I have c++ problem here is the function and its error how can I change my function?
The statement

int finalCod [memory]={0};

is illegal because "memory" is a variable.

You need dynamic memory allocation:

either

int *finalCod = new int[memory];

or

int *finalCod = calloc( memory, 1 );

Do not forget to free the memory: for "new" use "delete", for "calloc" use "free()".
Reply:Yeah, what the heck is {0}?

You mean 0? Or 0th element of some array?
Reply:the code seems fine to me. chk whether the main program which generates a function call to codfile changes teh value of codlength? is codlength of type const?? u can try doing two things to remove ther error....first is directly initialize teh array to NULL and second u may try removing the const keyword.
Reply:The error is in this line:

const int memory=n*codlength/8;

memory is a const type. You cannot decide what goes into a constant type at run time. It has to be pre-decided.
Reply:Yeah, just remove const in line 3. The reason why it can't work is because you would be changing the value of memory every time you call the function, so just get rid of const. Or maybe in order for your array to work (int finalCod) with memory, it has to be also constant. So try getting rid of const when declaring memory.

Good Luck
Reply:the problem with ur function is that ur allocating memory statically without knowing exactly how much memory to allocate. this is not possible in c++. try the same thing dynamically using the 'new' operator.for eg int n=new int[];

In C++, What use do we have for constants instread of variables?

2009-07-14T20:13:00.001-07:00

an example would be

const double PI=3.14;

for(float x=PI;whatever;x++){

cout%26lt;%26lt;x%26lt;%26lt;endl;

}

that was just an example of using constants;

but you could do the same without using constants;

double PI=3.14;

for(int x=PI;whatever;x++){

//This would also work

}

so what use do we have of using constants for somethings instread of variables

In C++, What use do we have for constants instread of variables?
Constants don't change, variables can change.

You can't mistakingly change a constant. For example like this:

if(pi=3.00){

//do something

}

If pi is a constant, you'll get an error message. If pi is a variable, you won't.
Reply:It's just so that no one else changes them. It also indicates to other programmers that the variable is never intended to change.
Reply:Variables use more memory. So if you have a large program you need to consider this.
Reply:Its just validation, it eliminates problems caused by changing variables.

It prevents you from accidentally changing its value and messing everything up. Its very professional. I must admit, I dont use them but I should do.

Beginner C++ help plz?

2009-07-14T20:13:00.000-07:00

Write a function that accepts an array of integers and an integer that represents the size of the array. This function will reverse the order of the array. Ex:

if a[0] = 4, a[1] = 2, a[2] = 9, a[3] = 89;

After executing this function:

a[0] = 89, a[1]=9, a[2] = 2, a[3] = 4

#include %26lt;iostream%26gt;

using namespace std;

int main()

{

const int SIZE = 4;

int a[4] = {4, 2, 9, 89};

for (int count = 0; count %26lt; SIZE; count++)

b[count] = a[count];

return 0;

}

I have this so far, I can't get any farther, can u please make some changes.

Beginner C++ help plz?
This is a very very common question especially on job interviews so it is important that you have as an elegant as solution as possible.

void Reverse(int* array, int length)

{

int i, tmp;

for (i=0; i%26lt;len/2; i++)

{

tmp = array[i] ;

array[i] = array[len-i-1] ;

array[len-i-1] = tmp;

}

note there is an even more elegant solution using the ^ (xor) operation but that is not for the beginner.

**** Note I edited the second line from

array[i] = tmp

to

array[len-i-1]

}
Reply:What do you need to do here honey? What does b[count]=a[count] do ? It makes and exact copy of the array, right?

Whare you want to do is flip the array. You want that line to be something like this:

b[count]=a[SIZE-count];

This may look wrong at first, but try it out, you will be plesantly surprised.

Do the math for it and you will see what is happening.

b[0]=b[4-0]

b[1]=b[4-1]

and so on....

:)

Actually I also like the other guys answer for this one, that is a much more elegant solution.

In C++ is writing a copy constructor the same as overloading the assignment operator?

2009-07-14T20:12:00.003-07:00

Lets say

class x{

X(const%26amp; X rhs){

y = rhs.y;

z = rhs.z;

};

private:

double y;

int z;

};

Doing that will allow for assignment too right???

Does that make

X y2;

X y1 = y2; // wont y1.X(y2) be called any way???

work how it seems like it should?

thanks!

In C++ is writing a copy constructor the same as overloading the assignment operator?
They are closely related. When you write one, you should write the other.

The other answerers are correct. The copy constructor is used when you write code like the following:

MyClass X = Y; //invokes copy constructor

MyClass X(Y); //also invokes copy constructor

whereas the operator = is called when you write code like the following:

MyClass X: //invokes default constructor

X = Y; //invokes operator =

Since you rarely see code like "MyClass X = Y", you might be tempted to skimp on the copy constructor. Don't. There's another sneaky place you often find copy constructors: passing variables by value. The standard template library does this ALL THE TIME, so if you have vectors or lists in your code, be aware of this.

MyClass Y; //invokes default constructor

DoSomething(Y); //calls copy constructor

std::vector%26lt;MyClass%26gt; myVector;

// (pretend we added a bunch of items to vector here)

myVector.push_back(Y); //invokes copy constructor. May also invoke copy constructor on other items already added if vector resizes.

std::sort(myVector); //invokes operator= on any items that move

From the programmer's standpoint, one key thing to remember is that when you write the operator =, you MUST clean up anything you're pointing at already. For example, if you have a pointer in your class, you should free that pointer before copying the value from the right-hand side. Copy constructors tend to be faster than operator= for this reason.

Hope this helps.
Reply:It will call the copy constructor but there's a different between both..copy constructor (or any other type of constructors) is called ONLY when you INITIALIZE a new instance of a certain class (statically or dynamically)..

so in your example, you used the assignment operator and the copy constructor was called because y1 was being initialized in that statement (X y1)

But, later on in the program...if you needed to write this:

y2=y1;

you will need the assignment operator overloading...and the copy constructor won't be called (No declaration/initialization here)
Reply:assignment is different from the construction of an object. Copy constructor is called when an object is being defined and is being initialized with a value. Assignment operator is called when a value is assigned to an already defined object.

Note the difference between INITIALIZATION and ASSIGNMENT.

Thus,

X y2;

X y1 = y2;

will call the copy constructor and not the assignment operator.

survey research

I need help with printing and calling a C program... PLZ HELP!!?

2009-07-14T20:12:00.002-07:00

[HW] array of strings: Write a program to sort an array of strings into

alphabetical order. Use

const int N_MONTHS = 12;

const int STR_MAX = 20;

char month[N_MONTHS][STR_MAX] = {

"January",

"February",

"March",

"April",

"May",

"June",

"July",

"August",

"September",

"October",

"November",

"December"

};

as your test strings. Write the following functions.

● void print(char str[ ][STR_MAX], int n_str);

Write a function prints an array of strings. Parameter n_str is the number

of strings in array str[ ].

I need help with printing and calling a C program... PLZ HELP!!?
May be you can contact a C expert live at website like http://askexpert.info/ to help you code your assignment.

What does this mean line by line in C++?

2009-07-14T20:12:00.001-07:00

struct employee *allocemp(const char *name,const char *id,int age,double salary){

struct employee

*emp=new struct employee;

emp-%26gt;name=strdup(name);

strcpy(emp-%26gt;id,id);

emp-%26gt;age=age;

emp-%26gt;salary=salary;

return emp;

}

What does this mean line by line in C++?
Function definition "allocemp" ... likely meant as short-hand for allocate employee.

Semi-Line-by-line :

(1) ALLOCEMP is called with two c-string arguments, NAME and ID, an integral AGE, and a double floating point SALARY.

(2) Space for a new employee struct is allocated from the heap and a pointer stored in the local variable EMP (an employee struct pointer).

(3) Member variables of the newly allocated employee are then assigned per the data sent as arguments to this function ... c-strings are duplicated, as they are reference types.

(4) The value in EMP (a pointer to the new employee struct) is returned to the calling code.

So basically it's just allocating and initializing a new employee structure.

How should i used the searchpath parameter in C?

2009-07-14T20:12:00.000-07:00

the syntax is

char *searchpath(const char *file);

now in this what comes in between the brackets. what is const char *file and how to get the value or how will it return.

How should i used the searchpath parameter in C?
i didn't got it well but to search for a file by its extension just write down in the search title *.file extension for example *.exe or *.doc

In C#, how do you declare a constant such that it can be used in a different class?

2009-07-14T20:11:00.003-07:00

namespace abc

{

public class abcData

{

public const string str = "xyz";

}

}

I want the constant str to be accessible from another file that is referencing the "abc" namespace with "using abc;". How do I do this?

In C#, how do you declare a constant such that it can be used in a different class?
According to Object Oriented Design, you really shouldn't expose class properties directly. The task you're trying to accomplish can be done by using accessors with no Set method, ie. in this way:

namespace abc

{

public class AbcData

{

private const string str = "xyz";

public string AbcString

{

get { return str; }

}

}

}

In this way, you're hiding str, and exposing it using the Get Accessor method.
Reply:If you declare the constant as static, such as

public const static string str = "xyz";

then you should be able to reference the constant in another file by using abcData.str (if you're already "using abc;").

survey for money

C++ Help Please!?

2009-07-14T20:11:00.002-07:00

Hello, I am trying to run this class, but when I compile, it is telling me that "cout" and "endl" are undeclared integers....? I obviously just want the results to be output, but what do I have to do to fix this? Any help is appreciated.

class Rectangle

{

public:

Rectangle()

{

height= 0;

width = 0;

}

Rectangle(double h, double w)

{

height = h;

width = w;

}

double getHeight() // retrive the height to print in main

{

return height;

}

double getWidth() // retrive the width to print in main

{

return width;

}

double getArea()const

{

return height * width;

}

double getPerimeter()

{

return ((height * 2) + (width * 2));

}

private:

double height;

double width;

};

int main()

{

Rectangle rectangle1(5,50);

Rectangle rectangle2(3.5,35.9);

cout %26lt;%26lt; rectangle1.getArea() %26lt;%26lt; endl;

cout %26lt;%26lt; rectangle1.getPerimeter() %26lt;%26lt; endl;

cout %26lt;%26lt; rectangle2.getArea() %26lt;%26lt; endl;

cout %26lt;%26lt; rectangle2.getPerimeter() %26lt;%26lt; endl;

return 0;

}

C++ Help Please!?
Just add the following two lines at the start

#include %26lt;iostream%26gt;

using namespace std;
Reply:#include %26lt;iostream%26gt;

using std::cout;

using std::endl;

or, just

#include %26lt;iostream%26gt;

//and you have to use the namespace in your code.

std::cout%26lt;%26lt; blah %26lt;%26lt; cout::endl;

C++ Data Types?

2009-07-14T20:11:00.001-07:00

Lets say I want to do something like this:

#include %26lt;cstdlib%26gt;

#include %26lt;iostream%26gt;

#include %26lt;fstream%26gt;

#include %26lt;sstream%26gt;

#include %26lt;string%26gt;

const char *ip

int main(int argc, char *argv[])

{

std::cin %26gt;%26gt; ip

system("telnet" + ip);

}

what would the variable type of 'ip' have to be for this to work, and if it has to be converted from a certain type, how would I go about doing so?

C++ Data Types?
If you want to use direct string additions etc it would be better to use std::string and then convert it to character point for the system call as it wont support the string type

Here is the equivalent code

#include %26lt;cstdlib%26gt;

#include %26lt;iostream%26gt;

#include %26lt;string%26gt;

int main(int argc, char *argv[])

{

std::string ip;

std::cin %26gt;%26gt; ip;

ip = "telnet "+ip;

system(ip.c_str());

}

Run the program and enter the ip address

$a.out

127.0.0.1

Trying 127.0.0.1...

Connected to 127.0.0.1 (127.0.0.1).

Escape character is '^]'.

login: ^[[A^D

Password:
Reply:There isn't any variable type for ip because it has more than 1 dot. Try using 4 variables and concatenating them system("telnet" + ip1 + "." + ip2 + "." + ip3 + "." + ip4) and integer should be ok.

You could also use a char array.

C++ beginner help plz?

2009-07-14T20:11:00.000-07:00

const int size = 1000;

int sortarray[size];

int key = 0, j = 0;

int main(){

srand(time(0));

for(int i = 0; i %26lt; size; i++){ // starts the for loop

sortarray[i] = (rand()%10000) + 1; // makes numbers between 1 through 20 %/returns remainder

cout%26lt;%26lt;sortarray[i]%26lt;%26lt;" , ";

}

for(int i = 0; i %26lt; size; i++){ // starts the bubble sort

for(int j = size - 1; j %26gt; i; j--){ // starts the comparisons at the end of the array

if(sortarray [j] %26lt; sortarray[j - 1]){ // checks the current element with the previous one

key = sortarray[j]; // switches the elements if the conditions are met

sortarray[j] = sortarray[j - 1];

sortarray[j - 1] = key;

}

}

}

// formats the output prints to screen

cout%26lt;%26lt;endl%26lt;%26lt;endl;

for(int i = 0; i %26lt; size; i++){ // prints the sorted array

cout%26lt;%26lt;sortarray[i]%26lt;%26lt;", ";

}

return 0;

}

I wrote this code for bubble sort. How do I add a third array to fit the requirements of exchange sort method?

C++ beginner help plz?
Your code for bubble sort looks correct, but your question is confusing. Bubble sort is an exchange sort. Exchange sort is a general class of sorting algorithms, where the sort is executed by exchanging or swapping list elements.

I don't know what you mean by a third array (as you only have 1 array so far, the one to sort).
Reply:I suggest you to join C/C++ programming groups in yahoo for your programming doubts...

C++ follow up...?

2009-07-14T20:10:00.002-07:00

After spending some more time with this, the code now works. I would like some help in coding the error statement.

1) If the user enters an age, say below 1 or exceeding 120, the user shd get an error message "Warning, age must be between 1 and 120" hence(!(1%26lt;=ageValue%26amp;%26amp;ageValue%26lt;=120)), and then the user must be prompted again to enter a valid age.

2) If the user enters a non-int value, the message is "Error: invalid entry" and prgm exits the loop. Where would be best to input these two messages? THANKS!

/ reading values printing out input in reverse

//************************************...

#include%26lt;iostream%26gt;

using namespace std;

const int MAX=1000;

int main()

{

int ageValue[MAX];

int count=0;

char choice;

cout%26lt;%26lt;"Enter the age of the youngest family member:"%26lt;%26lt;endl;

cin%26gt;%26gt;ageValue[count];

cout%26lt;%26lt;"Are there any more family members?(Y for yes and N for no)"%26lt;%26lt;endl;

cin%26gt;%26gt;choice;

for(count=1; choice=='Y'||choice==

C++ follow up...?
I had to make some more changes to your code. I placed comments around the changes that I made.

#include%26lt;iostream%26gt;

using namespace std;

const int MAX=1000;

/* moved to here so all functions can use them */

int ageValue[MAX];

int count=0;

/* new function */

void inputAge()

{

cout%26lt;%26lt;"Enter the age of the youngest family member:"%26lt;%26lt;endl;

cin%26gt;%26gt;ageValue[count];

/* Error 2) */

if (!cin)

{

/* not exactly sure what you want done here. */

/* to exit program */

cout%26lt;%26lt;"Your other message!"

exit(1);

/* to only stop input, and then print the other values out

change the return value to a bool and return false */

/* return false; */

}

/* Error 1) */

else if (ageValue[count]%26lt;1||ageValue[count]%26gt;120)

{

cout%26lt;%26lt;"Your error message!"%26lt;%26lt;endl;

/* recall this method */

inputAge();

}

}

int main()

{

char choice;

/* call to new function */

inputAge();

cout%26lt;%26lt;"Are there any more family members?(Y for yes and N for no)"%26lt;%26lt;endl;

cin%26gt;%26gt;choice;

/* Placed in the below while instad of the for.*/

while (choice=='Y'||choice=='y')

/*for(count=1; choice=='Y'||choice=='y'; count++)*/

{

/* Added the count increment here */

count++;

/* call to new function */

inputAge();

cout%26lt;%26lt;"Are there any more family members?(Y for yes and N for no)";

cin%26gt;%26gt;choice;

}

cout%26lt;%26lt;"Thank you. The ages of your family in reverse order are:"%26lt;%26lt;endl;

/* Change the count%26gt;0 to count%26gt;=0 for it to print out the first entry as well */

while(count%26gt;=0)

{

cout%26lt;%26lt;" "%26lt;%26lt;ageValue[count];

/* Place the count decrement here */

count--;

}

return 0;

}
Reply:I have not had a chance to compile this, so I am not sure it is error-free. But I think that it should work fine.

#include%26lt;iostream%26gt;

using namespace std;

const int MAX=1000;

int IsInRange(float); //returns 1 if argument is in range.

int main()

{

int ageValue[MAX];

int count=0;

char choice;

float temp;

cout%26lt;%26lt;"Enter the age of the youngest family member:"%26lt;%26lt;endl;

cin%26gt;%26gt;temp;

while(!(IsInRange(temp))

{

cout%26lt;%26lt;"Age must be whole number between 1 and 120!"%26lt;%26lt;endl%26lt;%26lt;"Try again: ";

cin%26gt;%26gt;temp;

}

ageValue[count] = (int)temp;

cout%26lt;%26lt;"Are there any more family members?(Y for yes and N for no)"%26lt;%26lt;endl;

cin%26gt;%26gt;choice;

for(count=1; choice=='Y'||choice=='y'; count++)

{

cout%26lt;%26lt;"Enter the age of the next youngest person"%26lt;%26lt;endl;

cin%26gt;%26gt;temp;

while(!(IsInRange(temp))

{

cout%26lt;%26lt;"Age must be between 1 and 120!"%26lt;%26lt;endl%26lt;%26lt;"Try again: ";

cin%26gt;%26gt;temp;

}

ageValue[count] = (int)temp;

cout%26lt;%26lt;"Are there any more family members?(Y for yes and N for no)";

cin%26gt;%26gt;choice;

}

cout%26lt;%26lt;"Thank you. The ages of your family in reverse order are:"%26lt;%26lt;endl;

while(count%26gt;0)

{

count--;

cout%26lt;%26lt;" "%26lt;%26lt;ageValue[count];

}

return 0;

}

int IsInRange(float);

{

if(1%26lt;temp||temp%26gt;=120) return (0);

for(int i = 1;i%26lt;=119;i++)

{

if(i%26lt;temp%26amp;%26amp;temp%26lt;(i+1))

return(0);

else return(1);

}

}
Reply:Looking at your account, it is looks like you don't go back to your questions to award points, so why should we give you the answer?

survey questions

C++ programming help!?!?

2009-07-14T20:10:00.001-07:00

Anyways I can't get the 7th option for my menu to work.

Since, i don't know any other way to do this, i'm gonna post the program in parts....

#include "stdafx.h"

#include %26lt;iostream.h%26gt;

#include %26lt;iomanip.h%26gt;

int bank_menu(void);

const int SIZE=40;

struct

{

int cust_num;

int ssn;

char cust_name[SIZE];

float balance;

int act_type; //1=Checking; 2=Savings

}bank[10];

int main(int argc, char* argv[])

{

int choice;

int cust_index = -1;

do

{

choice = bank_menu();

if (choice == 1)

{

cout%26lt;%26lt;"You have chosen Load Customer into Structure.\n";

if (cust_index == 9)

cout%26lt;%26lt;"The structure is full.\n";

else

{

cust_index++;

bank[cust_index].cust_num = cust_index + 1;

cout%26lt;%26lt;"Enter Social Security Number: ";

cin%26gt;%26gt;bank[cust_index].ssn;

while (bank[cust_index].ssn %26lt; 100000000 || bank[cust_index].ssn %26gt; 999999999)

C++ programming help!?!?
EDIT: I added more at your SHORTENED VERSION link:

http://answers.yahoo.com/question/index?...

----------

I think the problem might be here in the transfer section:

cin%26gt;%26gt;transfer;

int c_index;

int s_index;

int i;

for (i=0; i%26lt;cust_index+1; i++)

{

if (bank[i].ssn == SSN)

{

if (bank[i].act_type == 1)

{

i=c_index;

}

else

{

i=s_index;

....

...

You have a loop for (i=0; i%26lt;cust_index+1; i++)

but you _might_ have not yet assigned a value to cust_index at the time you call the transfer section. Therefore, it's filled with whatever is in memory -- which may be a very, very large number -- and the loop travels on and on, incrementing 'i', until index i is completely off the array bank[] in:

if (bank[i].ssn == SSN)

...

...and the prog hangs/crashes ugly.

That's our 1st and main suspect. You can verify cust_index when calling the transfer section to be sure:

cout %26lt;%26lt; "cust_index is " %26lt;%26lt; cust_index;

...and thus ensure it's a "safe/small' value (and not negative!) before proceeding. Of course, this is just for debugging. You want to remove such stuff when you go final.

---- ----- ----- ----- -----

Loops are fequently the cause of program hang during run time, and it's hard to know if your code has hit some kind of lengthy or even infinite loop without visual indicators.

Optionally, when I'm debugging a tough problem and I need to inspect a loop variable, I might do something like this:

int iii= 20000;

while(iii--)

{

cout %26lt;%26lt; "\r iii is: " %26lt;%26lt; iii ;

///...other code here

}

This code will allow you to inspect the incrementor/decrementor "iii" as it clicks off without cluttering the screen full of numbers. The little "\r" keeps the cursor pinned to the start of the line.

Not only does this give you a strong visual clue, but the cout action allows you to CTR C keybreak out out of the loop easily if you can see the program is stuck in the loop. Much more amiable than calling taskmanager to kill a wayward execution, for example.

You can inspect all of the variables at run time in methods such as this til you pin down the culprit.

---

Use a standard comment by every piece of debug code so you can easily remove it all once fixed:

while(iii--)

{

cout %26lt;%26lt; "\r iii is: " %26lt;%26lt; iii ; //DEBUG ONLY

Then just do a find on string "DEBUG ONLY" for fast clean up.
Reply:You got to be kidding.

Sorry to be mean, but nobody here is going to debug your entire program - which is what you're asking.

Narrow down the problem and ask more specific question.
Reply:Set a break point at the beginning of the 7th choice and single step throught the code, watch the values of the variables. Since the program is crashing there, you are probably trying access memory that isn't valid (e.g. index problem) or something similar.

C++ program?

2009-07-14T20:10:00.000-07:00

I have to write a program that will read from a file and store it in an array. whenever i run the program however, it doesn't output the numbers that are in the file. please tell me what i'm doing wrong. Here's my code:

#include %26lt;iostream%26gt;

#include %26lt;fstream%26gt;

using namespace std;

int main()

{

const int ARRAY_SIZE = 10;

int numbers[ARRAY_SIZE];

int count;

ifstream inputFile;

inputFile.open("numbers.txt");

for (count = 0; count %26lt; ARRAY_SIZE; count++)

inputFile %26gt;%26gt; numbers[count];

inputFile.close();

cout %26lt;%26lt; "The numbers are: ";

for (count = 0; count %26lt; ARRAY_SIZE; count++)

cout %26lt;%26lt; numbers[count] %26lt;%26lt; " ";

cout %26lt;%26lt; endl;

return 0;

}

C++ program?
Is "numbers.txt" in the same directory as your executable? For example in Visual Studio; projectfolder/DEBUG/ or /RELEASE/.
Reply:shouldn't it be numbers[count] %26gt;%26gt;inputfile;

C++ help... Due tomorrow.?

2009-07-14T20:09:00.003-07:00

I need this program to work by tomorrow morning, but I can't tell that I'm doing anything wrong!!

Errors:

o_assignment5.cpp: In function `int main()':

o_assignment5.cpp:48: non-lvalue in assignment

o_assignment5.cpp:48: parse error before `-' token

o_assignment5.cpp:52: parse error before `)' token

o_assignment5.cpp:54: parse error before `)' token

o_assignment5.cpp: At global scope:

o_assignment5.cpp:61: parse error before `;' token

o_assignment5.cpp:61: syntax error before `++' token

o_assignment5.cpp:63: parse error before `;' token

o_assignment5.cpp:63: syntax error before `++' token

o_assignment5.cpp:66: syntax error before `%26lt;%26lt;' token

o_assignment5.cpp:70: syntax error before `.' token

Code:

#include %26lt;iostream%26gt;

#include %26lt;cstdlib%26gt;

#include %26lt;fstream%26gt;

#include %26lt;iomanip%26gt;

#include %26lt;cmath%26gt;

using namespace std;

const int SIZE = 15;

int colRow[SIZE][SIZE];

int userRow; // what the user of the program inputs for table width

int finalRow;

int userCol;

C++ help... Due tomorrow.?
The userRow - 1 = finalRow is not correct. I think that you mean: finalRow = userRow -1 and finalCol = userCol - 1

Try that it should compile.

But also I don't understand your loop code

the "int finalRow" will override the previously defined "finalRow" for the scope of the loop and likewise for the "int finalCol" loop.

HTH
Reply:userRow - 1 = finalRow

userCol - 1 = finalCol

Switch to

finalRow = userRow - 1

finalCol = userCol - 1
Reply:1. Look at your assignments for userRow and userCol from finalRow and finalCol

2. Your last loop isn't going to do what you intend it to.

Good luck.
Reply:1. You redeclared "outs" inside of main() ...don't do that.

2. Look at the following two lines:

userRow - 1 = finalRow // to get right number in array: rows

userCol - 1 = finalCol // to get right number in array: cols

You must place the variable to which a value is assigned in the LEFT side of the expression, like this: y = x - 1

3. One of your for() loops had a missing closing brace. Use proper indentation to find where this occurred.

C++ update....?

2009-07-14T20:09:00.002-07:00

I finally figured that sub-code out(with some hints from others)..For those who do not know, this is a simple way to read an input file containing scores for 3 exams(in this case, of 6 students), and output the highest in each exam...

//Sample Program 12- A non-interactive program to calculate student grades.

//************************************...

#include%26lt;iostream%26gt;

#include%26lt;iomanip%26gt;

#include%26lt;fstream%26gt;

#include%26lt;string%26gt;

using namespace std;

const int SIZE=6;

int GetHighValue(int array[]);

int main()

{

int exam1Array[SIZE];

int exam2Array[SIZE];

int exam3Array[SIZE];

int i=0;

string name;

ifstream inFile;

inFile.open("grades.dat");

if(!inFile)

{

cout%26lt;%26lt;"Unable to open input file, program abnormally ended";

return 1;

}

for(i=0; i%26lt;SIZE; i++)

{

inFile%26gt;%26gt;name%26gt;%26gt;exam1Array[i]%26gt;%26gt;exam2Array[...

}

GetHighValue(exam1Array);

cout%26lt;%26lt;"The highest for exam 1 is"%26lt;%26lt;GetHighValue(exam1Array)%26lt;%26lt;endl;

GetHighValue(exam2Array);

cout%26lt;%26lt;"The highest for exam 2 is"%26lt;%26lt;GetHighValue(exam2Array)%26lt;%26lt;endl;

GetHighValue(exam3Array);

cout%26lt;%26lt;"The highest for exam 3 is"%26lt;%26lt;GetHighValue(exam3Array)%26lt;%26lt;endl;

return 0;

}

int GetHighValue(/*in*/ int array[])

{

int highScore=0;

int i=0;

for(i=0; i%26lt;SIZE; i++)

{

if(array[i]%26gt;highScore)

highScore=array[i];

}

return highScore;

}

C++ update....?
You might want to retry the example code using STL library. It is amazing how easy it is to write over 60% of the code using C++ standard libraries.

It might not be so obvious in this small example, but as you move to bigger projects, you will see the benefit first hand.
Reply:sorry, i don't know, but you can try this site

surveys

C++ Program?

2009-07-14T20:09:00.001-07:00

I'm having a problem with my assignment. I can't get the program to do what it's suppose to do. Here is the thing I'm suppose to make.

Suppose you have a group of people who need to be transported on buses and vans. You can chargter a bus only if you can fill it. Each bus holds 50 people. You must provide enough vans for the 49 or fewer people who will be left over after you charter buses. Whrite a programthat accepts a number of people left over that must be placed on vans.

I can't get the modulus operator to work.

Here is what I have done so far:

//Project.cpp

#include %26lt;iostream.h%26gt;

#include %26lt;stdlib.h%26gt;

main()

{

const int size=50; //Declare size as a constant

int number_of_people;

int total;

int r;

//Total number of people

cout %26lt;%26lt; "What is the total number of people";

cin %26gt;%26gt; number_of_people;

total=number_of_people/size;

r=number_of_people%size;

cout %26lt;%26lt;"The total number of buses is ...

C++ Program?
1st the code is not complete

and i want to know what is the use of r

if r is the number of buses then u must use the divide sign"/" not the moduls sign "%"

if u r using r as the number of people remaning

then it must be in the form

r=number_of_people-(total*size);

note:the above line will give the right nswer because u r using int for total na dint for size, but if u use float it will not work and r will be zero

i hope this have solved ur problem
Reply:It's all good.

'total ' is the number of buses.

'r' is the number of poeple left who must go in vans.

Sample: 190 people = 3 busses (150 people) and 190%50 is 40 (same as 190-150 which you would expect).
Reply:Did you add ( } ) mark for your maiin() frame?
Reply:replace the line:

int total;

with this line:

float total;

the reason is that you can not store a float value in an integer which is what you are doing here:

total=number_of_people/size;

C++ modify program?

2009-07-14T20:09:00.000-07:00

i need it to stop when uncut=total my orginal prog. is

#include%26lt;cmath%26gt;

#include%26lt;string%26gt;

#include%26lt;iostream%26gt;

using namespace std;

int main()

{

double total, uncut;

const double restrate=.02;

total = 14000;

uncut = 2500;

cout %26lt;%26lt; "Year..............Acres" %26lt;%26lt; endl %26lt;%26lt; endl;

for(int k=0; k%26lt;20; k++)

{

cout %26lt;%26lt; k+1 %26lt;%26lt; ".............." %26lt;%26lt; uncut %26lt;%26lt; endl;

uncut += restrate * uncut;

}

getchar();

return 0;

}

C++ modify program?
add this line after uncut += restrate * uncut;

if (uncut==total) return 0;
Reply:if(uncut==total) break;

C++ Help Pllllease!!?

2009-07-14T20:08:00.003-07:00

Hello, now for this class, I have to add accessor and mutator functions for all the data fields, but I have no idea how... any help is appreciated!!!

#include %26lt;iostream%26gt;

using namespace std;

class Rectangle

{

public:

Rectangle()

{

height= 0;

width = 0;

}

Rectangle(double h, double w)

{

height = h;

width = w;

}

double getHeight() // retrive the height to print in main

{

return height;

}

double getWidth() // retrive the width to print in main

{

return width;

}

double getArea()const

{

return height * width;

}

double getPerimeter()

{

return ((height * 2) + (width * 2));

}

private:

double height;

double width;

};

int main()

{

Rectangle rectangle1(4,40);

Rectangle rectangle2(3.5,35.9);

cout %26lt;%26lt;"The area of Rectangle 1 is: " %26lt;%26lt; rectangle1.getArea() %26lt;%26lt; endl;

cout %26lt;%26lt;"The perimeter of Rectangle 1 is: " %26lt;%26lt; rectangle1.getPerimeter() %26lt;%26lt; endl;

cout %26lt;%26lt;"The area of Rectangle 2 is: " %26lt;%26lt; rectangle2.getArea() %26lt;%26lt; endl;

cout %26lt;%26lt;"The perimeter of Rectangle 2 is: " %26lt;%26lt; rectangle2.getPerimeter()

C++ Help Pllllease!!?
You can use mutators with the following prototype

void setHeight(double h);

void setWidth(double w);

Here are the code changes required

#include %26lt;iostream%26gt;

using namespace std;

class Rectangle

{

public:

Rectangle()

{

height= 0;

width = 0;

}

Rectangle(double h, double w)

{

height = h;

width = w;

}

double getHeight() // retrive the height to print in main

{

return height;

}

double getWidth() // retrive the width to print in main

{

return width;

}

/////////////////////////////////////...

void setHeight(double h) // set the height -- mutator

{

height = h;

}

void setWidth(double w) // set the width -- mutator

{

width = w;

}

/////////////////////////////////////...

double getArea()const

{

return height * width;

}

double getPerimeter()

{

return ((height * 2) + (width * 2));

}

private:

double height;

double width;

};

int main()

{

Rectangle rectangle1(4,40);

Rectangle rectangle2(3.5,35.9);

cout %26lt;%26lt;"The area of Rectangle 1 is: " %26lt;%26lt; rectangle1.getArea() %26lt;%26lt; endl;

cout %26lt;%26lt;"The perimeter of Rectangle 1 is: " %26lt;%26lt; rectangle1.getPerimeter() %26lt;%26lt; endl;

cout %26lt;%26lt;"The area of Rectangle 2 is: " %26lt;%26lt; rectangle2.getArea() %26lt;%26lt; endl;

cout %26lt;%26lt;"The perimeter of Rectangle 2 is: " %26lt;%26lt; rectangle2.getPerimeter();

/////////////////////////////////////...

// setting new values to rectangle 2

rectangle2.setHeight(5.55);

rectangle2.setWidth(1.11);

cout%26lt;%26lt;"\n AREA WITH NEW VALUES "%26lt;%26lt;endl;

cout %26lt;%26lt;"The area of Rectangle 2 is: " %26lt;%26lt; rectangle2.getArea() %26lt;%26lt; endl;

cout %26lt;%26lt;"The perimeter of Rectangle 2 is: " %26lt;%26lt; rectangle2.getPerimeter();

/////////////////////////////////////...

}
Reply:Accessors are your get functions (getHeight, getWidth). They provide access to the private variables in your class. You already have those.

What your class doesn't have is the mutators which are set functions (setHeight, setWidth). They need to take in a double parameter and make the private variable (eg. private double height) equal to that parameter.

Hope that gives you some clues.

C++ Help Please!?

2009-07-14T20:08:00.002-07:00

Ok guys. What I have to do is write an array that reads 10 numbers and displays how many are divisible by three. I wrote the code, but what I don't understand is that is always outputs 1 less then what the answer should be. What do I need to do to fix it? This is code I have made so far:

#include %26lt;iostream%26gt;

using namespace std;

int main()

{

const int TOTALNUMBERS = 10;

int numbers[TOTALNUMBERS];

// Read all numbers

for (int i = 0; i %26lt; TOTALNUMBERS; i++)

{

cout %26lt;%26lt; "Enter a number: ";

cin %26gt;%26gt; numbers[i];

}

// Find numbers divisible by 3

int div = numbers[0];

for (int i = 0; i %26lt; TOTALNUMBERS; i++)

if (div / 3)

div = numbers[i];

cout %26lt;%26lt; "Numbers divisible by three: " %26lt;%26lt; div %26lt;%26lt;endl;

return 0;

}

Thanks!

C++ Help Please!?
Got a little logic error going on... You're OK up to the find numbers portion.

// Find numbers divisible by 3

int div =0; /* CHANGED; just to keep track of them */

/* Added brackets */

for (int i = 0; i %26lt; TOTALNUMBERS; i++) {

/*Use the MOD operator. This will yield the remainder of the division */

if ((numbers[i]% 3)==0)

div ++;

}

cout %26lt;%26lt; "Numbers divisible by three: " %26lt;%26lt; div %26lt;%26lt;endl;

return 0;

}

P.S. Your FOR condition is fine!

survey monkey

C++ Help! This is juat a small part of my program so it's very raw. I want the prgm to read an input file ....

2009-07-14T20:08:00.001-07:00

//Sample Program 12- A non-interactive program to calculate student grades.

//************************************...

#include%26lt;iostream%26gt;

#include%26lt;iomanip%26gt;

#include%26lt;fstream%26gt;

#include%26lt;cstring%26gt;

using namespace std;

const int SIZE=20;

int main()

{

int exam1Array[SIZE];

int exam2Array[SIZE];

int exam3Array[SIZE];

int highScore;

int count=0;

string name[SIZE];

ifstream inFile;

inFile.open("grades.dat");

if(!inFile)

{

cout%26lt;%26lt;"Unable to open input file, program abnormally ended";

return 1;

}

inFile%26gt;%26gt;name[count]%26gt;%26gt;exam1Array[count]%26gt;%26gt;...

highScore=0;

for(count=0; count%26lt;SIZE; count++)

if(array[count]%26gt;highScore)

highScore=array[count];

cout%26lt;%26lt;highScore%26lt;%26lt;endl;

return 0;

}

C++ Help! This is juat a small part of my program so it's very raw. I want the prgm to read an input file ....
in your loop, you forgot the brackets. change:

for(count=0; count%26lt;SIZE; count++)

if(array[count]%26gt;highScore)

highScore=array[count];

cout%26lt;%26lt;highScore%26lt;%26lt;endl;

return 0;

to

for(count=0; count%26lt;SIZE; count++)

{

if(array[count]%26gt;highScore)

{

highScore=array[count];

cout%26lt;%26lt;highScore%26lt;%26lt;endl;

}

}

return 0;
Reply:Are you really supposed to go online to get others to do your assignments for you?
Reply:The following code will work in VC++ 2005:

[Create a new Win32 Console Project]

#include "stdafx.h"

const int SIZE=20;

int _tmain(int argc, _TCHAR* argv[])

{

float exam1Array[SIZE];

float highScore = 0.0;

int count=0;

int error;

FILE * inFile;

fopen_s(%26amp;inFile,"c:\\temp\\junk\\grades....

if(feof(inFile))

{

printf("Unable to open input file, program abnormally ended");

return 1;

}

fseek(inFile, 0L, SEEK_SET );

while (!feof(inFile))

{

error = fscanf_s(inFile,"%f",%26amp;exam1Array[count])...

if (exam1Array[count] %26gt; highScore)

highScore = exam1Array[count];

count++;

}

fclose(inFile);

printf("Highest Score is = %f",highScore);

getchar();

return 0;

}

The grades.dat file should look like:

53.5

84.2

98.1

with no Carriage return after the last grade.

This is something you can play with in the mean time. Happy learning! Remember to give me points for this...
Reply:buy K%26amp;R book on C called "The C Programming Language, Second Edition".. it has all this easy stuff in it... if you are starting with C .. you should really have this book... it is the basis of all C

C++ comp programming...basic question?

2009-07-14T20:08:00.000-07:00

what is wrong here:

class CC

{ public;

void set(int, int);

void print () const;

CC () ;

CC (int, int);

bool CC (int, int);

private:

int u;

int v;

};

C++ comp programming...basic question?
This is a easy one.

Constructors can't have return types.

bool CC (int, int);

CC can't return bool.
Reply:It's useful to learn what your compiler errors mean, and where to look, debugging is one of the most useful skills.

Use a search engine to find what the error your compiler is giving you means, and see if you can work it out from there. It will make programming a whole lot easier in the long run. Of course, ask here as a last resort by all mean.

Looks like a typo, you put the colon after private, but obviously missed shift when typing it after public

public;

should be

public:
Reply:You need a : after public.

class CC

{

public:

void set(int, int);

C++ need help changing a prog.?

2009-07-14T20:07:00.002-07:00

this is my current program i need to change it so i can input the years.

#include%26lt;cmath%26gt;

#include%26lt;string%26gt;

#include%26lt;iostream%26gt;

using namespace std;

int main()

{

double total, uncut;

const double restrate=.02;

total = 14000;

uncut = 2500;

cout %26lt;%26lt; "Year..............Acres" %26lt;%26lt; endl %26lt;%26lt; endl;

for(int k=0; k%26lt;20; k++)

{

cout %26lt;%26lt; k+1 %26lt;%26lt; ".............." %26lt;%26lt; uncut %26lt;%26lt; endl;

uncut += restrate * uncut;

}

getchar();

return 0;

}

C++ need help changing a prog.?
Prompt the user to inpu the data u want. cout out a statement asking to input the data then use cin to get the input.

To do this u need to type

cin%26gt;%26gt;"data";

after prompting the input

this will set ur input data to equal the variable for the data. Put this in the input section of your program. You would do it like this, lets call the new variable "data":

#include%26lt;cmath%26gt;

#include%26lt;string%26gt;

#include%26lt;iostream%26gt;

using namespace std;

int main()

{

double total, uncut;

const double restrate=.02;

double data=0;

total = 14000;

uncut = 2500;

cout%26lt;%26lt;"Input the data needed"%26lt;%26lt;endl; //this will promt the data to be entered

cin%26gt;%26gt;data; //this will recive the data

cout %26lt;%26lt; "Year..............Acres" %26lt;%26lt; endl %26lt;%26lt; endl;

for(int k=0; k%26lt;20; k++)

{

cout %26lt;%26lt; k+1 %26lt;%26lt; ".............." %26lt;%26lt; uncut %26lt;%26lt; endl;

uncut += restrate * uncut;

}

getchar();

return 0;

}

C++ Help! Why is the identifier undeclared?

2009-07-14T20:07:00.001-07:00

Ok... I have this code that I wrote that takes 10 numbers and outputs the amount divisible by 3, but the one and only error message reads that 'i' in line 18 is an undeclared integer. What do I need to do to fix this? Here's the code. Thanks guys.

#include %26lt;iostream%26gt;

using namespace std;

int main()

{

const int TOTALNUMBERS = 10;

int numbers[TOTALNUMBERS];

// Read all numbers

for (int i = 0; i %26lt; TOTALNUMBERS; i++)

{

cout %26lt;%26lt; "Enter a number: ";

cin %26gt;%26gt; numbers[i];

}

//Find numbers divisible by 3

int div = 0;

for (int i = 0; i %26lt; TOTALNUMBERS; i++);

{

if ((numbers[i] % 3)==0)

div++;

}

cout %26lt;%26lt; "Numbers divisible by three: " %26lt;%26lt; div %26lt;%26lt;endl;

return 0;

}

C++ Help! Why is the identifier undeclared?
You have a semicolon at the end of the for statement. This 'closes' the for loop and its associated 'i' is dropped.
Reply:It might be that since you already declared i in the other for loop, try taking off the int.

for( i=0;

I see nothing else
Reply:It is a semi-colon at the end of your loop that should not be there.
Reply:for (int i = 0; i %26lt; TOTALNUMBERS; i++);

theres a semicolon at end of second for loop where there shouldn't be one

online survey

C++ help ?

2009-07-14T20:07:00.000-07:00

#include %26lt;iostream%26gt;

using namespace std;

class SimpleCat

{public:

SimpleCat(int age, int weight);

SimpleCat(SimpleCat %26amp;);

~SimpleCat();

int getAge()const {return itsAge;}

void setAge(int ager) {itsAge = ager;}

void setWeight(int weighter) {itsAge = weighter;}

private:

int itsAge;

int itsWeight;};

SimpleCat::SimpleCat(int age, int weight)

{itsAge = age;

itsWeight = weight;}

SimpleCat::SimpleCat(SimpleCat %26amp;)

{cout %26lt;%26lt; "SimpleCat Copy Constructor\n";}

SimpleCat %26amp; FunctionOne(SimpleCat%26amp; theCat);

int main(){cout %26lt;%26lt; "Making a Cat\n";

SimpleCat Frisky(5,10);

cout %26lt;%26lt; "Inside Main.Frisky is " %26lt;%26lt; Frisky.getAge() %26lt;%26lt; " years old.\n"%26lt;%26lt; "Passing Frisky into FunctionOne\n";

FunctionOne(Frisky);

cout %26lt;%26lt; "Inside Main.Frisky is " %26lt;%26lt; Frisky.getAge() %26lt;%26lt; " years old.\n" %26lt;%26lt; "Passing Frisky into FunctionOne\n";

system("PAUSE");}

SimpleCat %26amp; FunctionOne(SimpleCat %26amp; theCat){

cout %26lt;%26lt; "Inside Function One\n" %26lt;%26lt; "Setting Frisky Age=10 %26amp; Weight=60\n";

theCat.setAge(10);

return(theCat);}

C++ help ?
I don't see "new" in your code, but the new operator provides dynamic storage/memory allocation.

I'm curious, what did you change to get it to compile? Thanx...

C++ Help Please!?

2009-07-14T20:06:00.002-07:00

Ok so I had to find the smallest number in a 10-number array and I did that with this.

#include %26lt;iostream%26gt;

using namespace std;

int main()

{

const int TOTALNUMBERS = 10;

int numbers[TOTALNUMBERS];

// Read all numbers

for (int i = 0; i %26lt; TOTALNUMBERS; i++)

{

cout %26lt;%26lt; "Enter a number: ";

cin %26gt;%26gt; numbers[i];

}

// Find the smallest

int min = numbers[0];

for (int i = 1; i %26lt; TOTALNUMBERS; i++)

{

if (min %26gt; numbers[i])

min = numbers[i];

}

cout %26lt;%26lt; "The smallest number is " %26lt;%26lt; min %26lt;%26lt;endl;

return 0;

}

But now I have to find the index of the smallest number, and I have no idea of how to do that. Any tips? Thanks alot guys.

C++ Help Please!?
see for the additions i have made:

#include %26lt;iostream%26gt;

using namespace std;

int main()

{

const int TOTALNUMBERS = 10;

int numbers[TOTALNUMBERS],location;

// Read all numbers

for (int i = 0; i %26lt; TOTALNUMBERS; i++)

{

cout %26lt;%26lt; "Enter a number: ";

cin %26gt;%26gt; numbers[i];

}

// Find the smallest

int min = numbers[0];

location=0;

for (int i = 1; i %26lt; TOTALNUMBERS; i++)

{

if (min %26gt; numbers[i])

{min = numbers[i]; location=i;}

}

cout %26lt;%26lt; "The smallest number is " %26lt;%26lt; min %26lt;%26lt;" at location "%26lt;%26lt;location+1%26lt;%26lt;endl;

return 0;

}
Reply:I would set up a for loop like for(int i = 0; i %26lt; 10; i++) and a variable called "smallestIndex" = 0 which would loop through the array and test the numbers[i] with the current smallest indexand

if(numbers[i] %26lt; numbers[smallestIndex]);

smallestIndex = i;
Reply:Seeing that this is probably a homework assignment, I'll describe what you need to do:

Create an extra variable (near //Find the smallest) to hold the index.

Then, inside the loop, when you are trying to find the smallest index, not only copy the value of the smallest value (min=numbers[i]), but also its index. Store it in the variable you created.

Finally, in your cout statement, print the value of this variable.

..........C++ code?

2009-07-14T20:06:00.001-07:00

How would I get it to do display the following patterns using the FOR statement?

*********

********

*******

******

so on…

*********

********

*******

******

so on…

Such as:

*

**

***

****

*****

so on…

I have tried using the WHILE for several hours. Unknowing I had to use the FOR all along.

#include %26lt;iostream%26gt;

using std::cout;

using std::cin;

using std::endl;

[code]

int main()

{

//declare variables

const char asterk = '*';

int a = 9;

int b = 0;

while (a %26gt; 0)

{

b = a;

while (b %26gt; 0)

{

cout %26lt;%26lt; asterk;

b = b - 1;

}

a = a - 1;

cout %26lt;%26lt; endl;

}

//end while

return 0;

} //end of main function

..........C++ code?
//Decreasing

int main()

{

//declare variables

const char asterk = '*';

int a = 0;

int b = 0;

For(a = 9;a %26gt; 0 ; a--)

{

For(b=a;b %26gt; 0 ; b--)

{

cout %26lt;%26lt; asterk;

}

cout %26lt;%26lt; endl;

}

//end while

return 0;

} //end of main function

//Increasing

int main()

{

//declare variables

const char asterk = '*';

int a = 0;

int b = 0;

for(a = 1; a %26lt; 9;a++)

{

for(b = a; b %26gt; 0 ;b--)

{

cout %26lt;%26lt; asterk;

}

cout %26lt;%26lt; endl;

}

//end while

return 0;

} //end of main function
Reply:assume the max possible number of * on a line is n.

1) descreasing:

for(int i=n; i%26gt;0; i--)

for(int j=0; j%26lt;i; j++)

cout%26lt;%26lt;"*";

cout%26lt;%26lt;endln;

2) increasing:

for (int i=0; i%26lt;n; i++)

for (int j=0; j%26lt;i; j++)

cout%26lt;%26lt;"*";

cout%26lt;%26lt;endln;

What is wrong with this c++ program??

2009-07-14T20:06:00.000-07:00

I am trying to get this program to work but i can't - I am very new to this

#include %26lt;iostream%26gt;

using namespace std;

int Main()

{

const int seconds_per_minute = 60;

const int minutesPerHour = 60;

int timeInSeconds; // time that is input -- totally in seconds

int hours; // how many hours in time

int minutes; // how many minutes in time

int seconds; // how many seconds in time

cout %26lt;%26lt; "Enter the time in seconds only: " %26lt;%26lt; endl;

cin %26gt;%26gt; timeInSeconds;

seconds = timeInSeconds % seconds_per_minute;

minutes = timeInSeconds / seconds_per_minute % minutesPerHour;

hours = timeInSeconds / seconds_per_minute * seconds_per_minute;

// check the values of seconds, minutes, and hours

return 0;

}

What is wrong with this c++ program??
It would be helpful to know the error if any this program is trying to generate. Obviously you are trying to get it to display the Values you have setup.

This is going to sound stupid, but the code looks fine with exception to the modulo calls. If your trying to use the remainder's for your values that might be where you are getting messed up (i.e. the % calls). If your trying to output your code definitely need to insert some cout's in there. This is pretty much all I can tell you from the pseudo code without knowing the error it generates. ALWAYS output your variables to see what is going on before committing it to a function.
Reply:First you need to check if they have inputted over 60 seconds(1 minute) so you can calculate minutes. Do the same for hour, and check to see if you have at least 60 minutes to calculate hrs.

after "cin%26gt;%26gt; timeInSeconds" it should be:

if(timeInSeconds%26gt;=60) then //check to see if you have atleast 60 seconds

{

minuteSoFar = timeInSeconds / seconds_per_minute;

//minuteSoFarwill give you the number of minutes so far

//before calculating hours.Also since it is integer it wont give

//you a decimal value..e.g 70/60 will give you 1 not 1.167.

seconds=timeInSeconds%seconds_per_minute

// left over amount from mins, which is the seconds

if(minutesSoFar%26gt;=60)//check to see you have at least 60mins(1hr)

{

hours= minuteSoFar/minutesPerHour;

minutes=minuteSoFar%minutesPerHour;

}

else

hours = 0;

}

else

{

hours = 0;

minutes = 0;

}

cout %26lt;%26lt; "Hours = " %26lt;%26lt; hours %26lt;%26lt;endl;

cout %26lt;%26lt; "Minutes = " %26lt;%26lt; minutes %26lt;%26lt;endl;

cout %26lt;%26lt; "Seconds =" %26lt;%26lt; seconds %26lt;%26lt;endl;

return 0;

i think that should be right
Reply:hours = timeInSeconds / seconds_per_minute * seconds_per_minute;

operations "/" and "*" has equal priority so they will be executed consequently, one after one: first, the time in seconds will be diveded by the number of seconds per minute ( i.e. we get number of minutes), then this result will be multiplied by the number of seconds per minute.
Reply:Well, for starters, 'Main' should be 'main'.

salary survey

C++ I only have one error, I have the closing bracket at the end so what is wrong? Error C1004?

2009-07-14T20:05:00.003-07:00

#include %26lt;iostream%26gt;

#include %26lt;string%26gt;

using namespace std;

const char Semi_colon = ';';

const string VERB1 = "guess";

int main ()

{

string firstLine;

int play;

int escape;

string guess;

int cl18=0; // make sure the semi-colon

int cl20=0; // make sure the semi-colon

string clue;

;int start=0;

start:

cout %26lt;%26lt; "This program was created by Amanda Harmony";

cout %26lt;%26lt; "Would you like to play?\n Press 1 for yes, and 0 for no.\n";

cin %26gt;%26gt; play;

if ( play == 1 )

{

goto cl1;

};

if ( play == 0 )

{

goto ender;

};

cl1:

cout %26lt;%26lt; "I am not real." %26lt;%26lt; endl;

cin %26gt;%26gt; guess;

if ( guess == "Star Trek" )

{

cout %26lt;%26lt; "CORRECT!";

if (guess != "Star Trek")

{

cout %26lt;%26lt; "INCORRECT To guess again, press 1. To quit, press 0.\n";

cout %26lt;%26lt; "Guess again?";

cin %26gt;%26gt; guess;

firstLine = "Star Trek";

cin %26gt;%26gt; escape;

if ( escape == 0 )

{

goto cl1;

};

cl2:

cout %26lt;%26lt; "I take place in the future." %26lt;%26lt; endl;

cout %26lt;%26lt; "Guess?" %26lt;%26lt; endl;

cin %26gt;%26gt; guess;

if (guess == "Star Trek")

{

cout %26lt;%26lt; "CORRECT!";

if (guess != "Star Trek")

{

cout %26lt;%26lt; "INCORRECT To guess again, press 1. To quit, press 0.\n";

cout %26lt;%26lt; "Guess again?";

cin %26gt;%26gt; guess;

firstLine = "Star Trek";

cin %26gt;%26gt; escape;

if ( escape == 0 )

{

goto cl2;

};

cl3:

cout %26lt;%26lt; "There is a whole new generation of me." %26lt;%26lt; endl;

cout %26lt;%26lt; "Guess?" %26lt;%26lt; endl;

cin %26gt;%26gt; guess;

if (guess == "Star Trek")

{

cout %26lt;%26lt; "CORRECT!";

if (guess != "Star Trek")

{

cout %26lt;%26lt; "INCORRECT To guess again, press 1. To quit, press 0.\n";

cout %26lt;%26lt; "Guess again?";

cin %26gt;%26gt; guess;

firstLine = "Star Trek";

cin %26gt;%26gt; escape;

if ( escape == 0 )

{

goto cl3;

};

cl4:

cout %26lt;%26lt; "I take you to new places where no one has been before." %26lt;%26lt; endl;

cout %26lt;%26lt; "Guess?" %26lt;%26lt; endl;

cin %26gt;%26gt; guess;

if (guess == "Star Trek")

{

cout %26lt;%26lt; "CORRECT!";

if (guess != "Star Trek")

{

cout %26lt;%26lt; "INCORRECT To guess again, press 1. To quit, press 0.\n ";

cout %26lt;%26lt; "Guess again?";

cin %26gt;%26gt; guess;

firstLine = "Star Trek";

cin %26gt;%26gt; escape;

if ( escape == 0 )

{

goto cl4;

};

cl5:

cout %26lt;%26lt; "I have a doctor with me at all times." %26lt;%26lt; endl;

cout %26lt;%26lt; "Guess?" %26lt;%26lt; endl;

cin %26gt;%26gt; guess;

if (guess == "Star Trek")

{

cout %26lt;%26lt; "CORRECT!";

if (guess != "Star Trek")

{

cout %26lt;%26lt; "INCORRECT To guess again, press 1. To quit, press 0.\n";

cout %26lt;%26lt; "Guess again?";

cin %26gt;%26gt; guess;

firstLine = "Star Trek";

cin %26gt;%26gt; escape;

if ( escape == 0 )

{

goto cl5;

};

cl6:

cout %26lt;%26lt; "Sometimes I can't believe my ears." %26lt;%26lt; endl;

cout %26lt;%26lt; "Guess?" %26lt;%26lt; endl;

cin %26gt;%26gt; guess;

if (guess == "Star Trek")

{

cout %26lt;%26lt; "CORRECT!";

if (guess != "Star Trek")

{

cout %26lt;%26lt; "INCORRECT To guess again, press 1. To quit, press 0.\n";

cout %26lt;%26lt; "Guess again?";

cin %26gt;%26gt; guess;

firstLine = "Star Trek";

cin %26gt;%26gt; escape;

if ( escape == 0 )

{

goto cl6;

};

cl7:

cout %26lt;%26lt; "I have been around since 1965." %26lt;%26lt; endl;

cout %26lt;%26lt; "Guess?" %26lt;%26lt; endl;

cin %26gt;%26gt; guess;

if (guess == "Star Trek")

{

cout %26lt;%26lt; "CORRECT!";

if (guess != "Star Trek")

{

cout %26lt;%26lt; "INCORRECT To guess again, press 1. To quit, press 0.\n";

cout %26lt;%26lt; "Guess again?";

cin %26gt;%26gt; guess;

firstLine = "Star Trek";

cin %26gt;%26gt; escape;

if ( escape == 0 )

{

goto cl7;

};

cl8:

cout %26lt;%26lt; "I am the story of a mission." %26lt;%26lt; endl;

cout %26lt;%26lt; "Guess?" %26lt;%26lt; endl;

cin %26gt;%26gt; guess;

if (guess == "Star Trek")

{

cout %26lt;%26lt; "CORRECT!";

if (guess != "Star Trek")

{

cout %26lt;%26lt; "INCORRECT To guess again, press 1. To quit, press 0.\n ";

cout %26lt;%26lt; "Guess again?";

cin %26gt;%26gt; guess;

firstLine = "Star Trek";

cin %26gt;%26gt; escape;

if ( escape == 0 )

{

goto cl8;

};

cl9:

cout %26lt;%26lt; "I have been on TV and the movies." %26lt;%26lt; endl;

cout %26lt;%26lt; "Guess?" %26lt;%26lt; endl;

cin %26gt;%26gt; guess;

if (guess == "Star Trek")

{

cout %26lt;%26lt; "CORRECT!";

if (guess != "Star Trek")

{

cout %26lt;%26lt; "INCORRECT To guess again, press 1. To quit, press 0.\n ";

cout %26lt;%26lt; "Guess again?";

cin %26gt;%26gt; guess;

firstLine = "Star Trek";

cin %26gt;%26gt; escape;

if ( escape == 0 )

{

goto cl9;

};

cl10:

cout %26lt;%26lt; "I see stars and planets scientists have never seen." %26lt;%26lt; endl;

cout %26lt;%26lt; "Guess?" %26lt;%26lt; endl;

cin %26gt;%26gt;guess;

if (guess == "Star Trek")

{

cout %26lt;%26lt; "CORRECT!";

if (guess != "Star Trek")

{

cout %26lt;%26lt; "INCORRECT To guess again, press 1. To quit, press 0.\n";

cout %26lt;%26lt; "Guess again?";

cin %26gt;%26gt; guess;

firstLine = "Star Trek";

cin %26gt;%26gt; escape;

if ( escape == 0 )

{

goto cl10;

};

cl11:

cout %26lt;%26lt; "I take about an hour at the time" %26lt;%26lt; endl;

cout %26lt;%26lt; "Guess?" %26lt;%26lt; endl;

cin %26gt;%26gt; guess;

if (guess == "Star Trek")

{

cout %26lt;%26lt; "CORRECT!";

if (guess != "Star Trek")

{

cout %26lt;%26lt; "INCORRECT To guess again, press 1. To quit, press 0.\n ";

cout %26lt;%26lt; "Guess again?";

cin %26gt;%26gt; guess;

firstLine = "Star Trek";

cin %26gt;%26gt; escape;

if ( escape == 0 )

{

goto cl11;

};

cl12:

cout %26lt;%26lt; "My ships don't travel by sea." %26lt;%26lt; endl;

cout %26lt;%26lt; "Guess?" %26lt;%26lt; endl;

cin %26gt;%26gt; guess;

if (guess == "Star Trek")

{

cout %26lt;%26lt; "CORRECT!";

if (guess != "Star Trek")

{

cout %26lt;%26lt; "INCORRECT To guess again, press 1. To quit, press 0.\n";

cout %26lt;%26lt; "Guess again?";

cin %26gt;%26gt; guess;

firstLine = "Star Trek";

cin %26gt;%26gt; escape;

if ( escape == 0 )

goto cl12;

};

cl13:

cout %26lt;%26lt; "I know asians, African-Americans and Russians." %26lt;%26lt; endl;

cout %26lt;%26lt; "Guess?" %26lt;%26lt; endl;

cin %26gt;%26gt; guess;

if (guess == "Star Trek")

{

cout %26lt;%26lt; "CORRECT!";

if (guess != "Star Trek")

{

cout %26lt;%26lt; "INCORRECT To guess again, press 1. To quit, press 0.\n";

cout %26lt;%26lt; "Guess again?";

cin %26gt;%26gt; guess;

firstLine = "Star Trek";

cin %26gt;%26gt; escape;

if ( escape == 0 )

{

goto cl13;

};

cl14:

cout %26lt;%26lt; "John Belshi and Dan Ackroyd made fun of me." %26lt;%26lt; endl;

cout %26lt;%26lt; "Guess?" %26lt;%26lt; endl;

cin %26gt;%26gt; guess;

if (guess == "Star Trek")

{

cout %26lt;%26lt; "CORRECT!";

if (guess != "Star Trek")

{

cout %26lt;%26lt; "INCORRECT To guess again, press 1. To quit, press 0.\n";

cout %26lt;%26lt; "Guess again?";

cin %26gt;%26gt; guess;

firstLine = "Star Trek";

cin %26gt;%26gt; escape;

if ( escape == 0 )

{

goto cl14;

};

cl15:

cout %26lt;%26lt; "Although not my business my interprise keeps me going." %26lt;%26lt; endl;

cout %26lt;%26lt; "Guess?" %26lt;%26lt; endl;

cin %26gt;%26gt; guess;

if (guess == "Star Trek")

{

cout %26lt;%26lt; "CORRECT!";

if (guess != "Star Trek")

{

cout %26lt;%26lt; "INCORRECT To guess again, press 1. To quit, press 0.\n ";

cout %26lt;%26lt; "Guess again?";

cin %26gt;%26gt; guess;

firstLine = "Star Trek";

cin %26gt;%26gt; escape;

if ( escape == 0 )

{

goto cl15;

};

cl16:

cout %26lt;%26lt; "I like to keep my own space." %26lt;%26lt; endl;

cout %26lt;%26lt; "Guess?" %26lt;%26lt; endl;

cin %26gt;%26gt; guess;

if (guess == "Star Trek")

{

cout %26lt;%26lt; "CORRECT!";

if (guess != "Star Trek")

{

cout %26lt;%26lt; "INCORRECT To guess again, press 1. To quit, press 0.\n";

cout %26lt;%26lt; "Guess again?";

cin %26gt;%26gt; guess;

firstLine = "Star Trek";

{

cin %26gt;%26gt; escape;

if ( escape == 0 )

{

goto cl16;

};

cl17:

cout %26lt;%26lt; "I have a cult following." %26lt;%26lt; endl;

cout %26lt;%26lt; "Guess?" %26lt;%26lt; endl;

cin %26gt;%26gt; guess;

if (guess == "Star Trek")

{

cout %26lt;%26lt; "CORRECT!";

if (guess != "Star Trek")

{

cout %26lt;%26lt; "INCORRECT To guess again, press 1. To quit, press 0.\n ";

cout %26lt;%26lt; "Guess again?";

cin %26gt;%26gt; guess;

firstLine = "Star Trek";

{

cin %26gt;%26gt; escape;

if ( escape == 0 )

{

goto cl17;

};

cl18: cout %26lt;%26lt; "Certain crystals empower me." %26lt;%26lt; endl;

cout %26lt;%26lt; "Guess?" %26lt;%26lt; endl;

cin %26gt;%26gt; guess;

if (guess == "Star Trek")

{

cout %26lt;%26lt; "CORRECT!";

if (guess != "Star Trek")

{

cout %26lt;%26lt; "INCORRECT To guess again, press 1. To quit, press 0.\n";

cout %26lt;%26lt; "Guess again?";

cin %26gt;%26gt; guess;

firstLine = "Star Trek";

{

cin %26gt;%26gt; escape;

if ( escape == 0 )

{

goto cl18;

};

cl19:

cout %26lt;%26lt; "A person names data resides on this ship." %26lt;%26lt; endl;

cout %26lt;%26lt; "Guess?" %26lt;%26lt; endl;

cin %26gt;%26gt; guess;

if (guess == "Star Trek")

{

cout %26lt;%26lt; "CORRECT!";

if (guess != "Star Trek")

{

cout %26lt;%26lt; "INCORRECT To guess, again press 1. To quit, press 0.\n";

cout %26lt;%26lt; "Guess again?";

cin %26gt;%26gt; guess;

firstLine = "Star Trek";

{

cin %26gt;%26gt; escape;

if ( escape == 0 )

{

goto cl9;

};

cl20:

cout %26lt;%26lt; "Kirk vs. Picard." %26lt;%26lt; endl;

cout %26lt;%26lt; "Guess?" %26lt;%26lt; endl;

cin %26gt;%26gt; guess;

if (guess == "Star Trek")

{

cout %26lt;%26lt; "CORRECT!";

}

if (guess != "Star Trek")

{

cout %26lt;%26lt; "INCORRECT To guess again, press 1. To quit, press 0.\n";

cout %26lt;%26lt; "Guess again?";

cin %26gt;%26gt; guess;

firstLine = "Star Trek";

{

cin %26gt;%26gt; escape;

if ( escape == 0 )

{

goto cl20;

};

ender:

return 0;

}

C++ I only have one error, I have the closing bracket at the end so what is wrong? Error C1004?
I'm not sure why you are doing it with "GOTO". I have re-implemented it for you, and it works with one loop, much easier to understand. I compiled and ran it, I'm pretty sure it does what you want.

It creates a list of clues, and each incorrect guess provides you with a different clue. If you guess it correctly, it ends.

[CODE START]

#include %26lt;iostream%26gt;

#include %26lt;string%26gt;

#include %26lt;vector%26gt;

using namespace std;

int main()

{

const string correctAnswer = "startrek";

const string guess = "Guess?";

int keepGoing;

string input;

//***

// Do we really want to play?

//***

cout %26lt;%26lt; "This program was created by Amanda Harmony";

cout %26lt;%26lt; "Would you like to play?\n Press 1 for yes, and 0 for no.\n";

cin %26gt;%26gt; keepGoing;

if (keepGoing == 0)

{

cout %26lt;%26lt; "Goodbye." %26lt;%26lt; endl;

return 0;

}

//***

// Establish our list of clues

// We should put this in a method but i'm being lazy.

//***

std::vector%26lt;string%26gt; clues;

string currentQ = "I am not real.";

clues.push_back(currentQ);

currentQ = "I take place in the future.";

clues.push_back(currentQ);

currentQ = "There is a whole new generation of me.";

clues.push_back(currentQ);

currentQ = "I take you to new places where no one has been before.";

clues.push_back(currentQ);

currentQ = "I have a doctor with me at all times.";

clues.push_back(currentQ);

currentQ = "Sometimes I can't believe my ears.";

clues.push_back(currentQ);

currentQ = "I have been around since 1965.";

clues.push_back(currentQ);

currentQ = "I am the story of a mission.";

clues.push_back(currentQ);

currentQ = "I have been on TV and the movies.";

clues.push_back(currentQ);

currentQ = "I see stars and planets scientists have never seen.";

clues.push_back(currentQ);

currentQ = "I take about an hour at the time";

clues.push_back(currentQ);

currentQ = "My ships don't travel by sea.";

clues.push_back(currentQ);

currentQ = "I know asians, African-Americans and Russians.";

clues.push_back(currentQ);

currentQ = "John Belshi and Dan Ackroyd made fun of me.";

clues.push_back(currentQ);

currentQ = "Although not my business my interprise keeps me going.";

clues.push_back(currentQ);

currentQ = "I like to keep my own space.";

clues.push_back(currentQ);

currentQ = "I have a cult following.";

clues.push_back(currentQ);

currentQ = "Certain crystals empower me.";

clues.push_back(currentQ);

currentQ = "A person names data resides on this ship.";

clues.push_back(currentQ);

currentQ = "Kirk vs. Picard.";

clues.push_back(currentQ);

for (int i=0; i %26lt; clues.size(); ++i) //let's go through all the clues

{

cout %26lt;%26lt; clues[i] %26lt;%26lt; endl;

cout %26lt;%26lt; guess %26lt;%26lt; endl;

cin %26gt;%26gt; input;

if (0 == input.compare(correctAnswer)) //star trek

{

cout %26lt;%26lt; "CORRECT!" %26lt;%26lt; endl;

return 0;

}

else

{

cout %26lt;%26lt; "INCORRECT To guess again, press 1. To quit, press 0." %26lt;%26lt; endl;

cin %26gt;%26gt; keepGoing;

if (keepGoing == 0)

{

return 0;

}

}

}

cout %26lt;%26lt; "Sorry, game over!" %26lt;%26lt; endl;

return 0;

}

[CODE END]
Reply:phew..

im glad im not taking that course..

OMGWTF..

im taking comp eng'g..

lol..

too bad just a freshmen..^^,

cant help..

C++ question!?

2009-07-14T20:05:00.002-07:00

int main()

{

const int PRIME=11213;

const RATE=15.6;

int i, x, y, w;

x=7;

y=3;

x= x+w;

PRIME= x+PRIME;

cout%26lt;%26lt; PRIME%26lt;%26lt;endl;

wages=RATE*36.75;

cout%26lt;%26lt; "Wages= " %26lt;%26lt; wages %26lt;%26lt;endl;

return 0;

whats wrong with this?

C++ question!?
1. int main()

2. {

3. const int PRIME=11213;

4. const RATE=15.6;

5. int i, x, y, w;

6. x=7;

7. y=3;

8. x= x+w;

9.

10. PRIME= x+PRIME;

11. cout%26lt;%26lt; PRIME%26lt;%26lt;endl;

12. wages=RATE*36.75;

13. cout%26lt;%26lt; "Wages= " %26lt;%26lt; wages %26lt;%26lt;endl;

14.

15. return 0;

-----

you use wages variable without declaration .

for example:

you have declare (x,y,w) at line 5 "int x,y,w;"

you have to declare wages:

double wages;
Reply:There are a lot of errors with your code

const RATE=15.6;

This should be const DOUBLE RATE, since its 15.6;

PRIME= x+PRIME;

PRIME is a const, meaning your not allowed to change its value, so using that line is not correct.

cout%26lt;%26lt; "Wages= " %26lt;%26lt; wages %26lt;%26lt;endl;

there's is no such thing as "wages"

I've posted the corrections to the code

#include %26lt;iostream%26gt;

using namespace std;

int main()

{

int PRIME= 11213;

const double RATE = 15.6;

int i, x, y, w;

x=7;

y=3;

x= x+w;

double wages = 0;

PRIME= x+PRIME;

cout%26lt;%26lt; PRIME%26lt;%26lt;endl;

wages=RATE*36.75;

cout%26lt;%26lt; "Wages= " %26lt;%26lt; wages %26lt;%26lt;endl;

return 0;

}

This displays:

"-858982240

Wages= 573.3"

cout%26lt;%26lt; PRIME%26lt;%26lt;endl; = "-858982240"

The reason for this is because you did not give a value to "w"

In order to correct this, just make w = 0;

cout%26lt;%26lt; "Wages= " %26lt;%26lt; wages %26lt;%26lt;endl; = "Wages= 573.3"

Which is what you hoped to get, I hope :P

Good luck programming

Feel free to msg me when you don't understand something, ill be gald to answer your question to the best of my ablilty
Reply:when u solve the c++ programs take it easy and think easy

its sure u achieve it bcoz this ur world

File handling in c++ coding help?

2009-07-14T20:05:00.001-07:00

Write a function int Move(const char* szDest, const char* szSrc) that moves the file existing at szSrc to szDest and returns 1 if successful, 0 otherwise

File handling in c++ coding help?
This is just a preliminary function which should help you get started. It is definitely not as flexible as mv, and calls remove() from the cstdio library. Rewrite as necessary.

int Move(const char* szDest, const char* szSrc)

{

ifstream infile;

ofstream outfile;

char c;

infile.open("oldfile.txt", fstream::in);

outfile.open("newfile.txt", fstream::out |fstream::trunc);

if (infile.good()) {while (infile.good())

{c=infile.get();

outfile.put(c);}

infile.close();

outfile.close();

remove("oldfile.txt");

}

else return 0;

return 1;

}

Help with my C++ program please!!?

2009-07-14T20:05:00.000-07:00

this is the error i am getting and don't how to fix it: cannot convert parameter 3 from 'const double' to 'double %26amp;'

this is my code:

#include %26lt;iostream%26gt;

#include %26lt;iomanip%26gt;

using std::cout;

using std::cin;

using std::endl;

using std::setprecision;

using std::fixed;

//function prototypes

void getInput(double %26amp;);

void calcBonus(double, double, double %26amp;);

void displayBonus(double);

int main()

{

//declare constant and variables

const double RATE = .1;

double sales = 0.0;

double bonus = 0.0;

//call funtions to get input

//call functions to calculate and display bonus amount

getInput(sales);

calcBonus(sales, bonus, RATE);

displayBonus(bonus);

//display output item

cout %26lt;%26lt; fixed %26lt;%26lt; setprecision(2);

return 0;

} //end of main function

//*****function definitions*****

void getInput(double %26amp;sales)

{

//enter input items

cout%26lt;%26lt;"Enter sales: ";

cin%26gt;%26gt;sales;

}//end of getInput function

Help with my C++ program please!!?
The problem is that your declaration of and the definition for "calcBonus" do not match up. Your declaration indicates that the third parameter is a non-const reference, yet you pass in a const. You should change the declaration of "calcBonus" to match that of your definition, and that should fix everything.

ASIDE:

It is common in C to use "output parameters" (i.e., parameters which are reference types) for reporting results. However, it is generally preferred among C/C++ programmers for parameters to be "input", only, and for the results to be given through the function's return type.

That is, it would be preferrable to use:

inline double calcBonus(double sales, double RATE)

{

return sales * RATE;

}

Note that I also declared the function "inline", because it would be a waste to create a new stack frame for such a simple multiplication operation. Also, I used "double" instead of "const double%26amp;", because double is small enough, that it doesn't make sense to pass by reference.
Reply:i don't understand your code what u want to do please write it properly.
Reply:The only function you have that takes at least 3 parameters is calcBonus(). And you are passing a const as the 3rd parameter but it wants a reference. If RATE was an ordinary double, this would work. However, a const is much like a hard-code number (0.1). And passing a reference without making it a const reference implies that the function has the ability to *change* that value. But you cannot change 0.1 to have a value of anything except 0.1. (Unless you are using an ancient version of Fortran!).

Easiest fix to this is to change the function declaration so that you just pass a double as the 3rd parameter and not a reference to a double.

surveys

In Winapi (Visual C++) , how do i get a string "EQ1" from my string list into my resource box "QUESTIONBOX" ?

2009-07-14T20:04:00.003-07:00

My current code is:

SetDlgItemText (hwnd, QUESTIONBOX, EQ1)

It returns an error, saying that it cannot convert from const int to const char :S

Hmm wat if i use SetWindowText..

Could someone paste in the exact code i need to type to make this work. thanks.

In Winapi (Visual C++) , how do i get a string "EQ1" from my string list into my resource box "QUESTIONBOX" ?
The following link from Microsoft shows an example on

how to use "SetDlgItemText"

http://msdn.microsoft.com/library/defaul...

SetDlgItemText(hDlg, IDS_POS, Roster[i].tchPosition);

May be this can help you

Please Help me out with this C++ problem ?

2009-07-14T20:04:00.002-07:00

Hi i want to make a program using vector... but that is little bit hard for me to do because i have little knowledge about vector.. I know about string and using class. But the following functiion should be use with vector.. If anybody has any idea please responce. Im writting in details so that it makes clear.

1) bool update(const string%26amp; name, int teleNum, const vector%26lt;string%26gt;%26amp; nameList, vector%26lt;int%26gt;%26amp; teleNumList) : This function updates the telephone number of the person name to teleNum. The nameList and the teleNumList are the name list and the corresponding telephone number list. If it fails to find the person, it returns false otherwise it returns true.

bool erase(const string%26amp; name, vector%26lt;string%26gt;%26amp; nameList, vector%26lt;int%26gt;%26amp; teleNumList) : This function erases the person and the corresponding telephone number of the person name. The nameList and the teleNumList are the name list and the corresponding telephone number list. If it fails to find the person, return fals or els true

Please Help me out with this C++ problem ?
goto codeproject.com in c++ stl u will get help

What is wrong with my C++ program? i am doing funtions and i am getting to errors that i don't know how to fix

2009-07-14T20:04:00.001-07:00

this is my code:

#include %26lt;iostream%26gt;

#include %26lt;string%26gt;

#include %26lt;iomanip%26gt;

using std::cout;

using std::cin;

using std::endl;

using std::string;

using std::setprecision;

using std::fixed;

//function prototypes

void getInput(string %26amp;, double %26amp;);

void calcFedTaxes(const double %26amp;, const double %26amp;, double %26amp;, double %26amp;, double %26amp;);

void calcNetPay(double %26amp;, double %26amp;, double %26amp;, double %26amp;);

void displayInfo(string %26amp;, double %26amp;, double %26amp;, double %26amp;);

int main()

{

//declare constants and variables

const double FWT_RATE = .2;

const double FICA_RATE = .08;

string name = "";

double salary = 0.0;

double fwtTax = 0.0;

double ficaTax = 0.0;

double netPay = 0.0;

//call funtions to get input

//calculate and display taxes and net pay

getInput(name, salary);

calcFedTaxes(FWT_RATE, FICA_RATE, salary, fwtTax, ficaTax);

calcNetPay(netPay, salary, ficaTax, fwtTax);

displayInfo(name, fwtTax, ficaTax, netPay);

return 0;

} //end of main function

What is wrong with my C++ program? i am doing funtions and i am getting to errors that i don't know how to fix
In calcFedTaxes, you're mixing const doubles with doubles between your declaration (line 14)

void calcFedTaxes(const double %26amp;, const double %26amp;, double %26amp;, double %26amp;, double %26amp;);

and in your implementation (line 50)

void calcFedTaxes(double %26amp;FWT_RATE, double %26amp;FICA_RATE, double %26amp;salary, double %26amp;fwtTax, double %26amp;ficaTax)

Codind in c++ oop?

2009-07-14T20:04:00.000-07:00

(7) Write a function int Move(const char* szDest, const char* szSrc) that moves the file existing at szSrc to szDest and returns 1 if successful, 0 otherwise

Codind in c++ oop?
Pretty basic stuff. Give it a shot, and we can help with any issues you might have.

survey monkey

Please Help me out with this c++ problem if any body knows !!!?

2009-07-14T20:03:00.003-07:00

Hi i want to make a program using vector... but that is little bit hard for me to do because i have little knowledge about vector.. I know about string and using class. But the following functiion should be use with vector.. If anybody has any idea please responce. Im writting in details so that it makes clear. th

1) void displayList(const vector%26lt;string%26gt;%26amp; nameList, const vector%26lt;int%26gt;%26amp; teleNumList) : This function displays the name and the corresponding number of all the persons in stored in nameList. The nameList contains the name list and teleNumList contains the corresponding telephone numbers. The pre-conditions are that both nameList and teleNumList have the same size and nth element of nameList corresponds to the nth element of teleNumList.

2)void append(const string%26amp; name, int teleNum, vector%26lt;string%26gt;%26amp; nameList, vector%26lt;int%26gt;%26amp; teleNumList) : This function appends the person name and the corresponding telephone number teleNum to the nameList and the teleNumList respectively.

Please Help me out with this c++ problem if any body knows !!!?
goto codeproject.com in c++ stl u will get help

Trying to finish compute coin C++ program?

2009-07-14T20:03:00.002-07:00

/***************************************...

* Program Name: Lab 12

* Author: Daniel Carr

* Date: 12 December 2007

* Course/Section: CSC-110-001

* Program Description: This program will tell what coins to give out for

* any amount of change from 1 cent to 99 cents.

*

*

**************************************...

/************************** Compiler Directives **********************/

#include %26lt;iostream%26gt;

using namespace std;

/*********************** Global Data Declarations ********************/

//None in this program.

/************************** Function Prototypes **********************/

//Sorts two numbers in ascending order

void input(int money);

int Calculatechange(int change);

int Calculatechange(int change);

void computecoin ( int%26amp; amount,int%26amp; coins, int denomiation);

void Output(int change, int quarters, int dimes, int nickles, int pennies);

/*************************************...

* Function Name: main

* Author: Daniel Carr

* Date: 8 November 2007

* Function Description:

*

* Pseudocode:

* Level 0

* -------

*

*

*

* Level 1

* -------

*

**************************************...

int main()

{

//Local variables

int money; //First user-entered number

int change; //Second user-entered number

/*************** Begin main Function Executables *****************/

//Variables

int quarters;

int dimes;

int pennies;

int nickles;

//Call function input

input(money);

//Call the function calculate

Calculatechange(change);

//Call function output

Output( change, quarters, dimes, nickles, pennies);

//Indicate to OS successful termination of program

return 0;

} //End main

/*************************************...

* Function Name: Input Money

* Author: Daniel Carr

* Date: 8 November 2007

* Function Description:

*

*

* Pseudocode:

* Level 0

* -------

* Enter amount of Money

*

* Level 1

* -------

* Enter amount of money

* Display "Enter amount of money (1-99)---%26gt;"

* Input Money

*

**************************************...

void input(int money)

//void inputmoney(float%26amp; x, //INOUT: First number to be sorted

// float%26amp; y) //INOUT: Second number to be sorted

{

//Local variables

cout %26lt;%26lt; "Enter amount of money (1-99)---%26gt;: ";

cin %26gt;%26gt; money;

} //End Input money

/*************************************...

* Function Name: Calculate Change

* Author: Daniel Carr

* Date: 8 November 2007

* Function Description: Calculate quarters, dimes, nickles, and pennies

*

*

* Pseudocode:

* Level 0

* -------

* Calculate Change

*

* Level 1

* -------

* Calcualte change

* Compute Quarters

* Compute Dimes

* Compute Nicklets and Pennies

* Level 2

* -------

* Compute Quarters

* Compute coin with Quarters, Change, and Q

* Compute Dimes

* Compute coin with Dimes, Change, and D

* Compute Nickles and Pennies

* Compute coin with Nickes Change and N,

*

*

*

*

*

*

*

**************************************...

int Calculatechange(int change)

{

//constants

const int q=25;

const int d=10;

const int n=5;

//arguements

int amount;

int denomiation;

int coins;

//Call the function computer coin

computecoin(amount,coins,denomiation)...

}

/*************************************...

* Function Name: Compute Coin

* Author: Daniel Carr

* Date: 8 November 2007

* Function Description: compute number of coin and amount left

*

*

* Pseudocode:

* level 0

* -------

* Compute number of coins and amount left

* level 1

* -------

* Compute number of coins and amount left

* coin=amount/demination

* amount = amount%demination

*

**************************************...

void computecoin ( int%26amp; amount,int%26amp; coins, int denomiation)

{

//Constistants

//Variables

//Arguements

coins = amount/denomiation;

amount= amount%denomiation;

amount %=denomiation;

}

/*************************************...

* Function Name: Display Change

* Author: Daniel Carr

* Date: 8 November 2007

* Function Description: compute number of coin and amount left

*

*

* Pseudocode:

* level 0

* -------

* Display Change

* level 1

* -------

* Display Change

* display Change%26amp; "coints can be given" EOL

* display "-----------------------" EOL

* display quarters %26amp; "Quarter(s)" EOL

* display dimes %26amp; "Dimes(s)" EOL

* display nickles %26amp; "Nickles(s) EOL

* display pennies %26amp; "Pennie(s) EOL

*

**************************************...

void Output(int change, int quarters, int dimes, int nickles, int pennies)

{

//Aruments

//Consistants

//Variables

cout %26lt;%26lt; change %26lt;%26lt; "coins can be given" %26lt;%26lt; endl;

cout %26lt;%26lt; "-------------------------------------" %26lt;%26lt; endl;

cout %26lt;%26lt; quarters %26lt;%26lt; "quarter(s)" %26lt;%26lt; endl;

cout %26lt;%26lt; dimes %26lt;%26lt; "dimes(s)" %26lt;%26lt; endl;

cout %26lt;%26lt; nickles %26lt;%26lt; "Nickle(s) %26lt;%26lt; endl;

cout %26lt;%26lt; pennies %26lt;%26lt; "Pennie(s) %26lt;%26lt; endl;

;}

Trying to finish compute coin C++ program?
U r missing quotes "...

"Nickle(s)"

"Pennie(s)"
Reply:Been through it a couple of times and the code seems ok but not sure about the way you've done your comments and pseudo code. C2001 is newline in constant %26gt;%26gt;

A string constant cannot be continued on a second line unless you do the following:

End the first line with a backslash.

Close the string on the first line with a double quotation mark and open the string on the next line with another double quotation mark.

http://msdn2.microsoft.com/en-us/library...

Can only assume the compiler is mistaking rems and pseudo for real code.

Please help PLEASE HELP IMMEDIATLY NEEDED FINAL PROJECT DUe tommorow c++ C++ !?!!!!!!! NEED GURU?

2009-07-14T20:03:00.001-07:00

//InventoryItem class file THIS IS THE CLASS FILE CPP FILE //COMING...................................

#ifndef INVENTORY_H

#define INVENTORY_H

#include %26lt;string%26gt;

using namespace std;

class InventoryItem

{

private:

string description;

string partNo;

int qty;

public:

void setDescription(string desc)

{description = desc;}

void setPartNumber ( string pNo)

{partNo = pNo; }

void setQTY ( int q)

{ qty = q; }

string getDescription() const

{ return description;}

string getPartNumber() const

{ return partNo;}

int getQTY() const

{ return qty; }

};

#endif

Please help PLEASE HELP IMMEDIATLY NEEDED FINAL PROJECT DUe tommorow c++ C++ !?!!!!!!! NEED GURU?
wtf this is jibberish

elaborate
Reply:Wat is the question? Wat do you want to do?
Reply:Not gibberish...some kind of programming, right? If it was GW Basic, maybe I could pull something out of my memory bank (get it, a computer reference) but this is way out of my league. I hope someone recognizes this and can help you.

C++ Errors?

2009-07-14T20:03:00.000-07:00

cannot convert parameter 1 from 'CString' to 'const char *'

cannot convert parameter 1 from 'const char [8]' to 'wchar_t'

I get Many errors involving "cannot convert" with different things involving CString, wchar_t or char. I had this working at one point but then i started the project over again and I think I am missing a few libraries.

Does anyone know whats causing these errors or what library/include I need?

C++ Errors?
to correct error 1, cast CT2CA. Example:

CHAR temp[100];

CString tempString = _T("hello world");

sprintf( temp, "%s", CT2CA( tempString) );

OR,

CString tempString = _T("hello world");

CT2CA temp(tempString);

to correct error 2, cast to CString, Example:

CHAR temp[100] = "hello world";

CString tempString;

tempString = CString(temp);

OR,

CString tempString = CString("hello world");
Reply:CString has a cast operator to LPCTSTR which is as good as const char * (unless you are coding for Unicode or something), so I'm not sure what's wrong there. Const char[8] is an array of chars while wchar_t is a single char. What's more, I believe wchar_t is a 16-bit char, so you wouldn't be able to swap between anything made out of char and anything made out of wchar_t. I believe MSDN mentions a function that copies from one to the other, but I don't know what it is called.
Reply:It's not due to missing libraries.

Please post the code in question so that it can be analyzed.
Reply:c# is way less confusing,see if u can use c# instead

online survey

C++; Ampersand trouble!?

2009-07-14T20:02:00.001-07:00

I have a function in a class, that is the type of another class. This "Example%26amp;" is in a class called "Answer."

Example%26amp; example() const;

I'm getting this error, as I try to return the instance of Example:

error C2440: 'return' : cannot convert from 'const Example' to 'Example %26amp;'.

What the heck does this mean, and how can I fix it so it will return properly? The function should be able to let the Answer class access the functions in Example. My instance is called myExample.

PLEASE HELP! (I've tried everything..)

C++; Ampersand trouble!?
so you have something like:

class Answer {

...

Example%26amp; example() const;

...

}

the problem is that you have marked the example function as const - which means that it can't modify the Answer object, and everything that it deals with is considered const too.

When you want to return some Example object that is part of Answer, you give away the permission to modify this Example, thus modifying the Answer object itself.

The solution would be to change the function to:

const Example%26amp; example() const;

(then you'll return a const reference to the Example which you won't be able to modify from outside)

or to:

Example%26amp; example();

(declare example as non-const, so it can do everything with Answer)

or even:

Example example() const;

(here you return a copy of the original Example object, so you it the original value can't be modified from outside)
Reply:%26amp; (Ampersand) is used to determine the actual address of the function. I've not yet encountered any function with an (%26amp;) before its header name. Try to use * (Asterisk) instead of this... If you rather want to use pointers... (^^,)

http://ronaldborla.blogsome.com/

C++ programming?

2009-07-14T20:02:00.000-07:00

int strcmp(const char *s,const char *t)

{

int i;

for (i = 0; s[i] == t[i]; i++)

if (s[i] == '\0')

return 0;

return s[i] - t[i];

}

and NOT

for (int i = 0; s[i] == t[i]; i++)

????

the compiler says obsolete binding...?

C++ programming?
in the for(int i=0 ...)

you want to use the i variable outside the scope (i is available only into the scope of for statement)

Do you use an old book to learn C++ ? or a book based on draft ?
Reply:If you define int i within a (for) loop you have to define it again in subsequent loops otherwise you will get the error.

So

int main()

{

for (int i = 0; i %26lt; 10; ++i )

;

for (i = 0; i %26lt; 10; ++i )

;

}

// is wrong

int main()

{

for (int i = 0; i %26lt; 10; ++i )

;

for (int i = 0; i %26lt; 10; ++i )

;

}

// is correct.
Reply:try declaring i out side the strcmp scope

C++ question?

2009-07-12T21:11:00.000-07:00

How can I change the type of double in the vector class to the struct track from the following code

struct Track

{

string trackName;

int trackDuration;

};

class Vector

{

private:

double *array;

int num_elements;

int max;

// doubles the capacity of the vector by allocating a new array and copying

// all elements over to it

// used by the push_back function when the vector becomes full

void grow();

public:

// Constructors to initialize the vector's member variables

Vector() { max = 10; array = new double[max]; num_elements = 0; }

// default constructor

Vector(int, double);

// initialize all elements to a specific value

// destructor

~Vector() { delete[] array; }

// Copy Constructor -- Added 4/30/07

Vector(const Vector%26amp;);

// Assignment operator -- Added 4/30/07

Vector%26amp; operator=(const Vector%26amp;);

void push_back(double); //

C++ question?
Astronomy C/C++ source code

Last updated 5 January 2007

From time to time, I'm asked to provide source code for doing some sort of astronomical calculation, or for providing direct access to the numerous compressed datasets on the Guide CD-ROM. In the future, I intend to gather information about and links to all such source code on this page.

If you don't see what you want here, please ask. I've got a fair bit of source code not yet posted simply because I've not gotten around to documenting it thoroughly yet.

The source code in question is written in C; click here for info on source code in other languages, or here for info on other C/C++ source code for astronomy. I use an extension of .CPP just to force the compiler to do certain error checking (type casts, etc.) that C++ compilers do better than C compilers. The only use I make of C++ is in Windows user interface (MFC) code, and I haven't posted any of that yet. However, Mark Huss has produced a C++ implementation of much of this code, and you can click here to download the ZIPped C++ version (about 128 KBytes). If that link fails, try this one.

I will post remaining code here from time to time. If you have any priorities (bits you would really like to see soon), please let me know; I can probably rearrange the order to get your code uploaded faster.

Changes: Assorted changes have been made in the past with the regrettable absence of a change log. In the future, the .ZIP file will contain a CHANGES.TXT file, explaining what's different about the newly-posted files.

Porting: As much as possible, I've stuck with ANSI C. Most of the code has already been used in 32-bit DOS and Windows; some has even run in 16-bit DOS and Windows. A make file for Linux is provided, and the code works there (but I've only used it to create a Linux version of Find_Orb, and not much else.) Mark Huss' C++ version also compiles in Linux. The only warning I'd offer in this regard is that I haven't dealt with a "wrong-end" byte order platform yet, and I am quite certain that some of the code will crash in grisly fashion on such systems.

Documentation: Almost all the code has quite thorough descriptions of how the innards work. (This requirement is the main one slowing posting of code. Some source has been posted for Find_Orb and Charon. But most of it is complex enough that posting it without explanation would not be very helpful.)

Copyright restrictions: All this code is free for use in non-commercial applications. If you wish to use any of it in a commercial application, please let me know; I'm not averse to a little bartering in such cases.

There are two exceptions to this: the RealSky/DSS image extraction software and the FITS image compression software are entirely in the public domain. (Certain parts of the RealSky/DSS code came from the Space Telescope Science Institute (STScI), and the FITS compression software is a very slightly modified version of an STScI package.)

For all the source code, I would ask that you inform me of any bugs you find, and if you make interesting improvements, I'd very much like to hear about them.

Astronomy source code in other languages (so far, only Java): Personally, I haven't written much of anything in a language other than C or C++ since 1988. (Not a good thing, I realize.) I get occasional questions about source code in Java and Pascal (surprisingly, not in BASIC... though you can click here for a list of BASIC programs from Sky %26amp; Telescope.)

In addition to his C++ astronomy source code, Mark Huss has written a lot of astronomy source code in Java, and has updated and improved it a bit recently (March 2002) as described in the following e-mail:

hi Bill,

I finally got things organized - the updated library, source, and info is

now available on my website: http://mhuss.com/AstroLib.html.

javadoc is an amazing thing - take a glance at

http://mhuss.com/AstroLib/docs/api/index...

regards,

--mark huss

(And from a previous e-mail...)

This is what's currently running the lunar phase info and 'darkest hours'

page on the DVAA website (http://dvaa.org). You should know, however, that I

used Meeus 'mystic formulas' instead of applying your 'witness the truth

thereof' philosophy in a couple of places for expediency ;-).

regards,

--mark

Some other implementation of assorted astronomical algorithms in C/C++: Mark Huss has written quite a bit of astronomy-related code in C++. P. J. Naughter has implemented much of Meeus' Astronomical Algorithms (second edition) in C++. You can click here for his code and info about it.

Source code for accessing Guide datasets and orbital elements: There is rather a lot of code in this category, and it has its own separate page. Click here for information on this subject. There are also some pieces of code to access some large catalogues here.

Source code for accessing JPL's DE ephemerides: This has grown to the point where it needed a page of its own. Click here for C/C++ source code for accessing JPL DE ephemerides.

Source code for RealSky/DSS image extraction: This is the same library used in Guide for image extraction; it's also used in version of SkyMap Pro, and, I suspect, in some other commercial astronomy software. You can read about it and download it from this page.

Source code for FITS image compression: A very slightly modified version of an STScI program. Click here for information and source code.

Source code and a DOS executable for tables of Galilean satellite events: This is the code I used to generate the lists of occultations, eclipses, transits, and shadow events shown in Guide. Click here for an example of the output of this program. The code is quite ugly, and I don't recommend its use very highly. Click here to download the source code and .EXE files (about 69 KBytes).

Source code for basic astronomical calculations: This file will eventually encompass all the low-level routines I use in Guide: nutation, aberration, computing planet positions from VSOP and PS_1996, refraction, lunar positions, the orientations of planets, coordinate systems, sidereal time...

At present, it has many of these, but not all. Here's a summary of the purpose of most of the .CPP files:

Click here to download the ZIPped code (about 93 KBytes). Here's some discussion of the meaning of the various source files supplied:

ALT_AZ.CPP: Code to convert RA/dec to alt/az, and galactic coordinates to RA/dec.

ASTEPHEM.CPP: The main function for the code to compute asteroid ephemerides. It demonstrates accessing orbital elements from the Guide disk, and then shows how to compute an RA/dec, magnitude, elongation, and other data based on using those elements to compute the asteroid position, and VSOP to compute the Earth's position. The most significant thing omitted right now is the topocentric offset.

ASTFUNCS.CPP: Some basic functions to set up asteroid/comet elements and to compute their locations (solving Kepler's equation and so forth.)

The Kepler's equation solution draws quite a bit of interest, so much so that there is a separate page discussing Kepler's Equation.

BIG_VSOP.CPP: Code to compute planetary positions from the full VSOP series, which is stored in binary form on the Guide CD-ROM. The logic is very similar to that used for the "truncated" VSOP (see VSOPSON.CPP), except that the function works by reading in pieces of a file; VSOPSON.CPP assumes the data file has been read into memory.

CLASSEL.CPP: Takes a state vector (position and velocity) and computes the "classical elements" (semimajor axis, eccentricity, mean anomaly, argument of perihelion, etc.) Currently, the FIND_ORB orbit determination software and the integrat numerical integration program make use of this; after computing an orbit in vector format, they use this routine to produce something in a form suitable for human consumption.

COLORS.CPP and COLORS2.CPP: Given, say, a B-V color value, it's possible to compute a "pretty good" V-R value. Similar conversions are possible between most other color indices, with varying degrees of accuracy. The general form is a polynomial, say,

index2 = a0 + a1 * index + a2 * index2 + a3 * index3 +....

These resemble Taylor series, though I suspect they are actually curve-fit polynomials. I got them from some Fortran snippets supplied by Brian Skiff, and they have been converted to C here.

Certain conversions are handled by inverting the polynomial. The need to do this indicates a very unreliable color conversion, to be used only in cases of dire emergency.

Also, code to convert Tycho B and V to Johnson B and V is given, along with a little piece of test code. (That Tycho-to-Johnson algorithm is one based the book that was distributed with the Hipparcos data, "Introduction and Guide to the Data." COLORS2.CPP is a more recent, and probably better, Tycho-to-Johnson piece of source code.)

COM_FILE.CPP: This is pretty much Guide-specific code. Guide goes through some odd hoops to draw comets as speedily as possible. One headache it has to deal with is that there isn't any consolidated set of comet orbital elements, the way there is with asteroids (e.g., MPCORB or the Lowell Observatory ASTORB). Instead, it has to dynamically combine "current comet" data from MPC with a list of historical comet data. The confused nature of comet designations makes that a pain (it's not always easy to match comets from one list with those from another). Also, Guide uses some pregenerated data to omit comets that are too faint to be of interest over a desired time span... all nifty stuff, and it helps Guide to run somewhat more briskly. But it's probably not of interest to most people.

COSPAR.CPP: Code to compute the "planet orientation" matrix for the Sun, all planets, and quite a few satellites. A few years ago, the IAU set up a committee to define pole positions and longitude systems for these objects. The pole position is usually defined to be a linear function in RA/dec, with the meridian intersecting the J2000 plane as another linear function. Often, some small trig terms are added to those linear functions.

At present, COSPAR.CPP includes many, but not all, of the satellites shown by Guide. Some (such as the "captured asteroids" of gas giants) have no defined orientations. Others (small inner objects such as Amalthea) just haven't been tackled by me yet (no big job to do, but not much interest, either).

DATE.CPP: Source code for the following calendrical systems: Julian, Gregorian, Hebrew, Persian (Jalaali and 'Modern Persian'), Islamic, and Chinese, and French Republican. Basically, you can do conversions between JD and the calendar systems.

DELTA_T.CPP: Code to compute Delta_T = TD - UT for any date, using a lookup table for years 1620 to 2002 and extrapolations beyond those ranges.

DE_PLAN.CPP: Code to compute very precise planetary positions using the PS-1996 series of Chapront. Includes Mercury through Pluto. To use this, you'll need to download this file of coefficients.

DIST_PA.CPP: Code to compute the distance and position angle between two spherical coordinates. Theoretically, this ought to be a straightforward task. In practice, there are an amazing number of ways to get roundoff/truncation errors and divides by zero, mostly involving how you deal with cases where the distance between the two points is small. I am reasonably sure now that this code evades all such cases.

EART2000.CPP: Code to compute the Earth's location relative to the Sun, in J2000 coordinates, using VSOP.

EASTER.CPP: Code to figure out the date of Easter for a given (Gregorian) year.

ELP82DAT.CPP: Code to compute the position of the moon using the ELP-82 (Ephemerides Lunaire Parisienne 1982) theory of Chapront and Chapront-Touzé. To make use of this code, you'll need to download this file of coefficients.

GETPLANE.CPP: Code to compute the location of any planet, or the Moon, relative to the Sun. The resulting vector is given in five different systems.

JD.CPP: Produces an "example" program showing the use of the functions in DATE.CPP. You can type in, say, "jd 10 7 1999", and be told what day 10 July 1999 corresponds to in assorted calendars. (You can also get the actual JD corresponding to that date, or type in, say, "JD 2451324.879" and get the calendar date... which was the original reason I wrote the program.)

JSATS.CPP: Code to compute the positions of the Galilean satellites, using Lieske's theory as given in Meeus' Astronomical Algorithms. Quite a few smaller terms are omitted.

LUNAR2.CPP: Code to compute the position of the moon, using the truncated series from Meeus' Astronomical Algorithms. This uses the same data file (VSOP.BIN) as the VSOPSON.CPP code discussed below.

MISCELL.CPP: Code for basic matrix functions (inverting an orthogonal matrix, rotation, setting identity matrices, etc.) Also code to handle the odd system used for variable star designations, and to provide a version of the C-language ctime() function that takes a JD and can work over a full time range (ctime only works between 1970 and 2028.) Also, this version gives plenty of formatting options (two-digit vs. four-digit years, DMY vs MDY vs YMD, months shown as digits, time shown in decimal hours/decimal minutes/decimal seconds/decimal days, etc.)

NUTATION.CPP: Computes the nutation of the earth's equator.

OBLIQUIT.CPP: Computes the obliquity of the earth's equator for dates from -8000 to +12000.

PERSIAN.CPP: Very special-purpose code, written to demonstrate how the Persian calendar is computed. Most people will either skip this, or just use the functions in DATE.CPP without really needing to know how the functions were put together.

PLUTO.CPP: Code to compute the position of Pluto, using the series given in Meeus' Astronomical Algorithms. This uses the same data file (VSOP.BIN) as the VSOPSON.CPP code discussed below.

PRECESS.CPP: Code to build the matrix used to convert coordinates between epochs, plus code to use those matrices to convert vectors, RA/dec coordinates, and ecliptic coordinates between epochs.

REFRACT.CPP: Contains functions to convert an observed altitude (one affected by refraction) to a true altitude (one that would be seen on an airless planet), or vice versa. Two different methods are provided. (See next paragraph for a third method.)

REFRACT4.CPP: Contains a more complex/sophisticated method of computing refraction, as given in the Explanatory Supplement to the Astronomical Almanac . This one does a numerical integration through the atmosphere, including effects due to observer altitude, temperature, barometric pressure, humidity, and wavelength of light being refracted. (But the end result is usually not all that different from that given by the two methods in the previous paragraph, except for very low altitudes or extreme conditions.)

RELATIVI.CPP: Code to test out the precession of Mercury's orbit due to general relativity, and also to test a quick and easy way to include first-order general relativity in orbit computations. The code may also be of interest because it integrates using the method of Encke, with a pretty good Runge-Kutta numerical integrator. Unfortunately, it could stand some documenting...

ROCKS.CPP: Code to compute positions for 25 faint, inner satellites of the gas giants. These are all modelled as precessing ellipses.

SHOWELEM.CPP: Code to take a set of orbital elements, and produce a human-readable text version, mostly resembling the MPC's "standard" eight-line format.

SSATS.CPP: Code to compute the positions of eight of Saturn's satellites (Mimas, Enceladus, Tethys, Dione, Rhea, Titan, Hyperion, Japetus), using the theory due to G. Dourneau.

VISLIMIT.CPP: This code computes the limiting visual magnitude, sky brightness, and extinction coefficients. It's basically lifted/ported from Brad Schaefer's article and code on pages 57-60, May 1998 Sky %26amp; Telescope, "To the Visual Limits".

VSOPSON.CPP: Code to compute planetary positions from a truncated VSOP series. That series is stored in binary form on the Guide CD-ROM, and you have to load it into a buffer to use this function. The logic is very similar to that used for the full VSOP (see BIGVSOP.CPP), except that that function works by reading in the file of coefficients on an "as needed" basis. This function (and several others listed on this page) require that you download this file of coefficient data.

Code to access astronomical datasets

UCAC-2 access: Significant enough that there is a separate page for the UCAC-2 code.

CMC-14 access: Significant enough that there is a separate page for the CMC-14 code.

Ax.0 access: Source code described and provided here.

USNO-B1.0 access: Some not well-documented (but probably still helpful) code to access USNO-B1.0 in its "original" 80GByte form is available here.

Tycho-2 CD access: Given the delays in getting Guide 8 out the door, I've had requests to provide some means of accessing the Tycho-2 CD-ROMs. (These disks have the additional advantage of being free, provided by ESA and USNO. Click here for details. Though I wouldn't be surprised if they're running low on disks.)

While I haven't done much with this data (except process it for use in Guide 8, of course), I have written a small utility to access Tycho-2 data for a given star. Click here to download the DOS software, source code, and documentation. Given this, you can extract positions, proper motion, and magnitudes (both Tycho and Johnson), with error estimates, for a given Tycho-2 star. (Both the transformation to the Johnson system and the error estimates are important. "Raw" Tycho mags match Johnson magnitudes only in a loose manner, and the Tycho-2 magnitude data runs the full range from extremely accurate to moderately accurate... you _must_ check error estimates to determine which is which.)

Artificial satellites: This has grown to the point where it deserved a page of its own. Click here for details on C/C++ code to compute artificial satellite ephemerides. (The currently-posted version is a nice improvement over some older artificial satellite code I posted previously. I'm leaving the old stuff because it's still getting a little use here and there.)

Symplectic integration: This single source file is derived from code posted by David Whysong on the newsgroup sci.astro.amateur. I simplified the code a bit and added a "test code" main() function. You can now get the results of our collaboration at David's Web site. It's a very interesting way of doing numerical integration, on several counts.

The major use for it is in cases where one wants to maintain certain constants of motion (total energy, angular momentum, etc.) Usual methods of numerical integration (Runge-Kutta, Adams-Bashforth, etc.) don't necessarily do a good job of this over really long integration spans. This was the reason for David's interest in the method. He is a graduate student working on globular cluster simulations. If, say, the total energy of his simulated globular increased (or decreased) over billions of years, we may assume that the whole thing would mysteriously explode with stars flying everywhere (or collapse down to a black hole). More details are given in the source code.

DIST.CPP: This code resulted from a discussion on the newsgroup sci.astro.amateur about how to compute the geodetic distance between two lat/lon points on the earth's surface. It incorporates two methods: one assumes a spherical earth, the other (much more complex) uses a method from

PAGE2.CPP: This code can take an RA/dec position and figure out the corresponding pages to be used in the Millennium Star Atlas, Uranometria, and Sky Atlas 2000. There's also a little snippet that takes a (lunar) lat/lon and figures out the corresponding page to be used from Antonín Rükl's Atlas of the Moon.

Source code for Charon: I've started the process of turning the Charon astrometry software into an open-source program. This begins by posting the source code for Charon (about 84 KBytes). You will also need the basic astronomical source code discussed above.

Why the source for Charon is being posted

Current state of the Charon source code

Overall structure of Charon

Why the source for Charon is being posted: I do not now, nor have I ever, regarded astrometry software as a commercially profitable idea. By a slight margin, I'm able to keep myself fed and indoors through sales of Guide; trying to sell Charon is not apt to help very much. By posting it, I hope to accomplish the following:

-- People will be able to improve/modify the source code to accomplish tasks of their own. (The basic idea behind almost all open source, of course.) With any luck, some of that code will return to me and I'll post it here for others to use. I know that some people have written Charon-like code and functions for their own project; I'm hoping that we can stop re-inventing wheels.

-- The number of users of Charon has risen to the point where I'm not doing too well at keeping up with requests for improvement. I've become a bottleneck to progress.

-- Posting the source code will probably encourage somebody to start work on making a version of Charon that does not require a Guide CD. If it can access catalog data from the Internet, then it would require no CD-ROM at all. In this case, people could do astrometry with Totally Free Software. This might encourage some people to enter the hobby.

-- Verifying the fact that the code does what I tell people it does becomes easier. Some people build their own astrometry software because they would rather not have to place trust in me and my software. Such trust would be well-placed, especially since the results of the software have been examined by dozens if not hundreds of people. (The worst risk in 'rolling your own' astrometry software is that it will usually be tested only by you, and not by dozens if not hundreds of people.) But being able to check the source code ought to relieve some anxieties.

Current state of the Charon source code: All of the rest of the source posted on this site has been cleaned up nicely and documented well enough to make it useful to somebody. Right now, this is not in the least true of Charon. You can use the source to satisfy curiosity about parts of Charon, and maybe to grab bits and pieces from the code. But there are some things I need to do to make it usable.

Charon is compiled with WATCOM C/C++, the only compiler I've got that can produce 32-bit DOS code that can access graphics. (Micro$oft's compiler can produce 32-bit DOS console applications, but none that access graphics.) I'm in the process of getting the make file into a usable form; right now, it runs across assorted directories and is not 'ready to go out of the box'.

There are parts of the code that run for hundreds of lines without the faintest trace of the residue of a comment. The code isn't particularly ugly (except for the enormous main() and parts of matcher.cpp), but figuring out what does what is a frightening prospect right now.

Overall structure of Charon: The program is overdue to be broken up into certain components. To a minor extent, this breakup is present now, but it's incomplete and Charon is really one big monolith at heart. This is really a shame, because astrometry software lends itself naturally to being broken into a set of component tasks.

Breaking Charon into components would make following the structure of the code much easier. It would let us rip out certain parts, replace them, or use them by themselves. The components (or, if you prefer, "near-components") are:

(1) Load an image from a file

(2) Find and build a list of stars in an image

(3) Get the RA/dec of an object at a given time

(4) Get stars from a catalog within a given radius of a given RA/dec

(5) Pattern-match the list of image stars to the list of catalog stars

(6) Display the results and interact with user

(7) Assorted minor functions

(8) (FUTURE, not yet implemented) Automated object detection

Load an image from a file: A piece that loads an image, be it FITS, SBIG, or other, into a standardized in-memory format. This is currently done using the load_image() function in load_img.cpp. A side note: it's possible that, in preference to writing one function that can load a zillion image formats, there should be a separate routine that can convert a zillion image formats into FITS. If I had it to do over again, I'd do it that way.

Find and build a list of stars in an image: Takes an image in the aforementioned standardized in-memory format and return a list of stars in it, with their pixel coordinates and brightnesses. The code in findstar.cpp does this right now. (I'm not totally thrilled with the job it does on noisy images; it often finds hordes of spurious stars in noise. Ideally, the code I wrote might get pitched in favor of SExtractor. I started playing with SExtractor and gave up, though; I had no real success in puzzling out what was supposed to do what.)

Get the RA/dec of an object at a given time: Given an object ID such as "V4191 Sgr" or "P/Linear S4" or "1997 XF11", and a date/time and observer position, this figures out the RA/dec of that object. The code in find_obj.cpp does this right now. If somebody tells Charon, for example, "Here's an image of asteroid 4179", Charon can figure out a rough RA/dec for 4179 at the time the image was taken, so it knows where to look for a pattern match.

In some ways, this is just a convenience. People can and do feed Charon images and just say, "Here's an image taken at about 14h51m12s, +10 43' 56"... go process it." But the 'convenience' is a major one.

Get stars from a catalog within a given radius of a given RA/dec: Given a catalog name and an RA/dec (normally provided by the preceding piece, but not always) and a radius, this piece grabs catalog data for that area and returns it in a standard way. Right now, assorted functions in grab_gsc.cpp do that. They can extract ACT, GSC, or GSC-ACT data from the Guide disks, or USNO Ax.0 or SAx.0 data from the CDs distributed by USNO, or GSC 1.2 data from the files that come from the STScI server. All the functions feed through the grab_catalog_stars() function in charon.cpp.

For Guide users, this is pretty nice; it means they can get all the data they need (comet/asteroid orbits, plus the GSC, plus other handy catalogs) all on one disk. For an open-source project, though, it'll be nice if the 'catalog grabbing' code can 'grab' from the two GSC CD-ROMs distributed by STScI, or via Internet. The first, at least, ought to be very straightforward. The second will be slightly trickier, but opens the program to anyone connected to the Internet... this would be a huge plus. I note that VizieR, for example, provides a way to ask for a given list of data from a catalog, specified by RA/dec and radius, using a single URL... almost exactly what we'd need for a stunt like this.

Right now, people have to shell out some money to buy the Guide disk, or the two GSC disks, to get into astrometry. Neither is really pricey, as astronomy products go ($89 and $69, respectively). But if trying out astrometry software was totally free, it might draw in some fresh blood.

Pattern-match the list of image stars to the list of catalog stars: Given a list of image stars (probably from the 'get stars from image' component), and a list of catalog stars (probably from the 'get stars from catalog' component), this part does the automated pattern-matching required to say, "Use the following transformation to go from image to RA/dec space and vice versa." The code for this is currently in matcher.cpp, and is a horror to behold... it's the sort of neighborhood where programmers only go in pairs.

Display the results and interact with user: This piece takes the image, lists of image stars and catalog stars, and transformation, and display the whole mess on the device of your choice. At present, this is done partly with code in the main( ) of charon.cpp, with a big chunk of it in dispimg.cpp and smaller pieces throughout the code. When applied to multiple images, this could allow for blinking. (The current blinking scheme in Charon is considerably less logical. I'd ignore it if possible.) This piece is intimately hooked into the entire user interface problem of how people can click on the image and manipulate it on-screen.

The previous components could be written in totally 'clean', generic ANSI source. Porting them to other OSes would be relatively straightforward. Unfortunately, the 'display/interact' component will be messy, heavily OS-dependent code.

Assorted minor functions: A whole slew of small pieces to do things such as write out MPC headers and reports, figure out which image star or catalog star is nearest to a given cursor position, provide ways to adjust settings, handle the list of MPC stations...

(FUTURE, not yet implemented) Automated object detection: Once the pattern matching code has done its work for a particular image, we can get a list of the RA/dec/magnitude values in that image. (Such lists would have value in and of themselves, of course.) Then we can take two or three such lists at different instants, and look for moving objects.

C++ queue help please.?

2009-07-12T21:10:00.003-07:00

template %26lt;typename Type%26gt;

struct Node{

Type data;

Node* next;

Node* previous;

}

template%26lt;typename Type%26gt;

class Queue{

void push(const Type%26amp;);

private:

Node%26lt;Type%26gt;* queueFront;

Node%26lt;Type%26gt;* queueBack;

};

// add an element to the back of the queue

template %26lt;typename Type%26gt;

void Queue%26lt;Type%26gt;::push(const Type%26amp; aValue){

// create a new node on the heap

Node%26lt;Type%26gt;* p = new Node%26lt;Type%26gt;;

// store the value into the node

queueBack = p;

p-%26gt;data = aValue;

if(queueFront == 0){

queueFront = p;

// if it is the first elment in the stack

// there is no previous so it is null

queueFront-%26gt;previous = 0;

queueFront-%26gt;next = 0;

}else{

p-%26gt;next = queueBack;

queueBack-%26gt;previous = p;

p-%26gt;previous = 0;

};

// make stack top point to the new node

// incriment the size

++queueSize;

};

when ever i try to call front, and return the value of the front item in the queue,i get an error if i have more than one element. What is happening??? thanks.

C++ queue help please.?
please try another compiler and

mention what error you r facing
Reply:Not sure if this is the problem, but I noticed that the two lines:

queueBack-%26gt;previous = p;

p-%26gt;previous = 0;

are counterproductive. At this point, queueBack == p, so the first line is useless.

I suspect you don't want that original queueBack = p and instead of an else off the if (queueFront == 0) test, you want an independent test of queueBack to decide how to set it.
Reply:There are too many problems, may be you can contact a C++ expert. Check websites like http://oktutorial.com/

salary survey

C++ Programming Help!!?

2009-07-12T21:10:00.002-07:00

Write a program that skips blanks in the input and prints the input text with no blanks at all.

So, for the input: Once there was a tree

The output would be: Oncetherewasatree

You should skip ALL the white spaces including tabs, if they appear in the input line.

This is what I have so far:

char* LeftTrim (char* const szTrim)

{

long lSpaceCount;

for (lSpaceCount = 0; *(szTrim + lSpaceCount) == ' '; ++lSpaceCount);

long lNextChar;

for (lNextChar = 0; *(szTrim + lSpaceCount + lNextChar - 1) != '\0';

*(szTrim + lNextChar) = *(szTrim + lNextChar + lSpaceCount), ++lNextChar);

return szTrim;

}

char* RightTrim (char* const szTrim)

{

long lSpaceCount;

for (lSpaceCount = lstrlen (szTrim) - 1; *(szTrim + lSpaceCount) == ' '; --lSpaceCount);

*(szTrim + lSpaceCount + 1) = '\0';

return szTrim;

}

#define TRIM(x) LeftTrim (RightTrim (x))

The problem is that I do not know how to make it to where anyone can input a text and it will return it with no spaces. Please help!!

C++ Programming Help!!?
here is the code to store the string without the spaces into a new variable...

for (i=0; sentence[i]!='\0';)

{

if (isalpha(sentence[i]))

nospace[j++]=sentence[i++];

else

i++;

}

nospace[j]='\0';

//variable string is the original text

/*nospace is the string without the spaces or any other special characters...*/
Reply:lookup the string tokenizer in the C++ libraries. Tokenize the input string by spaces ( " " ) and cycle through the tokenizer printing each word... that'll do it.

C question?

2009-07-12T21:10:00.001-07:00

What's wrong with the following program? I got syntax error.

I am just trying to make 2 strings to the same case, and compare them. So that strcasecmp ignores case while checkong whether 2 strings are the same. Thanks if u can help

int strcasecmp(const char* str1, const char* str2)

{

int cursor = 0;

while(str1[cursor] != '\0') {

if(str1[cursor] %26gt;= 'a' %26amp;%26amp; str1[cursor] %26lt;= 'z') {

str1[cursor] -= 32;

}

cursor++;

}

int cursor2 = 0;

while(str2[cursor2] != '\0') {

if(str2[cursor2] %26gt;= 'a' %26amp;%26amp; str2[cursor] %26lt;= 'z') {

str2[cursor2] -= 32;

}

cursor2++;

}

return strcmp(str1, str2);

C question?
I think you may need to move the definitionof cursor2 to the top of the file.

Make sure you subtract (char) 32, or, if you want to be more platform-independent, (char) 'a'-'A'.

Did you include string.h?

A lot of this stuff is supported in libraries:

if(strX[cursorX]%26gt;='a'%26amp;%26amp;strX[cursorX]%26lt;=...

if(!isupper(strX[cursorX]))

int isupper (char): #include %26lt;ctype.h%26gt;

strX[cursorX]-=32;

strX[cursorX]=toupper(strX[cursorX]);

char toupper(char): #include %26lt;ctype.h%26gt;

And your whole function itself:

int stricmp(const char *, const char *): #include %26lt;string.h%26gt;

survey

C++ Help Please!?

2009-07-12T21:10:00.000-07:00

So i have to design a class and have it contain this stuff, and I am having a hard time figuring it out. Any ideas?

I have to take this class and I'm supposed to be able to implement the class and write a test program that creates two Rectangle objects. Assign width 5 and height 50 to the first object and width 3.5 and height 35.9 to the second object. Display the properties of both objects and find their areas and perimeters.

This is what I have so far, but I do not know how to implement the class with the given parameters:

#include %26lt;iostream%26gt;

using namespace std;

class Rectangle

{

public:

Rectangle():height(1),width(1){}

Rectangle(int h, int w):height(h),width(w){}

inline double getArea()const

{

return height * width;

}

inline double getPerimeter()const

{

return (height * 2.0) + (width * 2.0);

}

private:

double height;

double width;

};

Any help is appreciated.

C++ Help Please!?
i made some corrections

class Rectangle

{

public:

Rectangle()

{

hieght= 0;

width = 0;

}

Rectangle(double h, double w)

{

hieght = h;

width = w;

}

double getHieght() // retrive the hieght to print in main

{

return hieght;

}

double getWidth() // retrive the width to print in main

{

return width;

}

double getArea()const

{

return height * width;

}

double getPerimeter()

{

return ((length * 2) + (width * 2));

}

private:

double height;

double width;

};

secondly

in the main part

define two objects

Rectangle rectangle1;

Rectangle rectangle 2;

rectangle1 = new Rectangle(5,50);

rectangle1 = new Rectangle(3.5,35.9);

cout%26lt;%26lt;rectangle1.getPerimeter(); and so on....

cout%26lt;%26lt;rectangle2.getPerimeter(); .....

GOOD luck

note: I'm afrid i forgot some parantheses so please double check on them :)

Please help me! Something is wrong with my C++ program?

2009-07-12T21:09:00.002-07:00

// bla bla

#include %26lt;iostream%26gt;

#include %26lt;iomanip%26gt;

using namespace std;

int main()

{

int seconds;

double distance;

int choice;

const double CarbonDioxide = 258.0;

const double Air = 331.5;

const double Helium = 972.0;

const double Hydrogen = 1270.0;

cout %26lt;%26lt; "\t\tSelect the disired gas\n\n";

cout %26lt;%26lt; "1. Carbon Dioxide\n";

cout %26lt;%26lt; "2. Air\n";

cout %26lt;%26lt; "3. Helium\n";

cout %26lt;%26lt; "4. Hydrogen\n";

cout %26lt;%26lt; "5. Quit\n";

cin %26gt;%26gt; choice;

if (choice == 1)

{

cout %26lt;%26lt; "enter seconds ";

cin %26gt;%26gt; seconds;

if (seconds %26lt; 0 || seconds %26gt; 30)

{

cout %26lt;%26lt; "You must enter seconds\n";

cout %26lt;%26lt; "that are in the range\n";

cout %26lt;%26lt; "of 0-30." %26lt;%26lt; endl;

}

else if (seconds %26gt; 0 || seconds %26lt; 30)

distance = seconds * CarbonDioxide;

cout %26lt;%26lt; "The total distance was.." %26lt;%26lt; distance %26lt;%26lt; endl;

}

else if (choice == 2)

{

cout %26lt;%26lt; "enter seconds ";

cin %26gt;%26gt; seconds;

if (seconds %26lt; 0 || seconds %26gt; 30)

{

cout %26lt;%26lt; "You must enter secon

Please help me! Something is wrong with my C++ program?
Yes what is happening is that this line:

distance = seconds * CarbonDioxide;

gets executed only if this condition evaluates to true:

if (seconds %26gt; 0 || seconds %26lt; 30)

Now what happens if it doesn't and you try to use the value inside distance?

A quick solution to the problem would be to replace

this:

double distance;

with this:

double distance = 0;
Reply:You misspelled 'desired'.

A bit of C++ help?

2009-07-12T21:09:00.001-07:00

virtual void draw() const = 0;

Does anyone know what "const = 0" means? I've seen just "const" before but what is the = 0 for?

Thanks!

A bit of C++ help?
I think the = 0 means the method is being defined as a pure virtual that must be overridden in any derived classes. The const before it flags something else to the compiler and isn't really related to the = 0.

Hope that helps.
Reply:it means an overridden draw() should also have the signature 'void draw()'.

Look at http://tydbits.com/blog/pavel/entry/brea... A full discussion seems to have happened on this bit.
Reply:take a look at it again

it's probably a typo
Reply:Are you sure it wasn't a typo? I'd look at it again
Reply:it means that the value default for const variables'll b 0. .

jj

2. Which of the following is the best explanation for the statement? char alph, * const ptr = &alph;?

2009-07-12T21:09:00.000-07:00

a). The value at the location pointed to by ptr cannot change.

b). The address and value in ptr cannot change.

c). The address in ptr cannot change.

d). The above statement generates a compiler error.

Give the best explanation

2. Which of the following is the best explanation for the statement? char alph, * const ptr = %26amp;alph;?
c

The pointer is CONST and therefore it (the pointer's value, or address to alph) cannot change.

land survey

Help Using C++?

2009-07-12T21:08:00.003-07:00

IN THE VOID MAIN WHERE WOULD YOU PUT THE ENDING BRACKET }

void main()

{

const int Number_Rows = 5; // Number of Rows.

const int Number_Columns = 10; // Number of Columns.

const float Prices[] = {100.00,75.00,50.00,25.00,5.00}; // Prices by Row

float Seats[Number_Rows][Number_Columns]; ... Seats Array.

float Price[Number_Rows];

int i;

int x,y;

// Ask for price for seat, input price.

for (i = 0; i %26lt; Number_Rows; i++)

{

cout %26lt;%26lt; "Please enter the rate for seats in row" %26lt;%26lt; (i + 1) %26lt;%26lt; endl;

cin %26gt;%26gt; Prices[i];

}

}

Help Using C++?
Looks to me like you already have it in the right place....

endl;

cin %26gt;%26gt; Prices[i];

}

}
Reply:http://www.dreamincode.net

All your C++ Questions answered Here

What's wrong with my C++ code on classes?

2009-07-12T21:08:00.002-07:00

This is my Class code, copied straight from my professor's notes. It's not working. I've got a final tomorrow on this stuff and need to know what's going wrong. The error that it keeps catching on is "new types may not be defined in the return type" under Stack::Stack().

#include %26lt;cstdlib%26gt;

using namespace std;

class Stack {

private:

int top;

int contents[100];

public:

Stack();

void stackPush(const int item);

void Pop();

int stackTop() const;

}

Stack::Stack()

{

top=-1;

}

void Stack::stackPush(const int item)

{

contents[++top]=item;

}

void Stack::Pop()

{

top--;

}

int Stack::stackTop() const

{

return contents[top];

}

What's wrong with my C++ code on classes?
You need a semicolon after the end of your class definition.

I need help with qsort in C++?

2009-07-12T21:08:00.001-07:00

// Documentation Begins

void qsort ( void * base, int num, int size, int ( * comparator ) ( const void *, const void * ) );

base

Pointer to the first element of the array to be sorted.

num

Number of elements in the array pointed at by base.

size

Size in bytes of each element in the array.

comparator

Function that compares two elements. The function shall follow this prototype:

int comparator ( const void * elem1, const void * elem2 );

The function must accept two parameters that are pointers to elements, type-casted as void*. These parameters should be cast back to some data type and be compared.

The return value of this function should represent whether elem1 is considered less than, equal, or greater than elem2 by returning, respectively, a negative value, zero or a positive value.

// End of qsort documentation

Lets say I have an array of Strings defined, how would I use qsort to alphabetically sorth them.

I need help with qsort in C++?
/************************************

Name: qsort.c

Sorry -- it's in C, but it's a short

walk to C++

For strings, change Ascend() and Descend() to handle strings...

int Ascend(const void *p1, const void *p2)

{

char *s1 = (char *)p1;

char *s2 = (char *)p2;

return strcmp(s1,s2);

}

*************************************/

#include %26lt;stdlib.h%26gt;

#include %26lt;stdio.h%26gt;

int num[]={1,3,5,4,2,9,0,8,6,7};

int Ascend(const void *p1, const void *p2)

{

int i=*(int *)p1;

int j=*(int *)p2;

return i-j;

}

int Descend(const void *p1, const void *p2)

{

int i= *(int *)p1;

int j= *(int *)p2;

return j-i;

}

int main()

{

int i;

printf("\nOrig array: ");

for (i=0; i%26lt;10; i++)

printf("%d ", num[i]);

qsort(num, 10, sizeof(int), Ascend);

printf("\nSorted array[Ascending]: ");

for (i=0; i%26lt;10; i++)

printf("%d ", num[i]);

qsort(num, 10, sizeof(int),Descend);

printf("\nSorted array[Descending]: ");

for (i=0; i%26lt;10; i++)

printf("%d ", num[i]);

}

I need help with my C++ program please!!! i am getting this error that i don' know how to fix - help!!?

2009-07-12T21:08:00.000-07:00

C ++ problem?

2009-07-12T21:07:00.003-07:00

whats the craic lads,

im writing a program at the moment and have an if statement in it

this is some of the code...

const int ROWS = 30;

const int START_X = 9;

const int START_Y = 4;

int start_x;

int start_y;

bool mouse_at_seat;

for(;;)

{

if(start_x %26lt; START_X + 2 || start_x %26gt; START_X + ROWS * 2 || start_y %26lt; START_Y + 2 ||start_y %26gt; START_Y + 10 || start_y - START_Y % 2!= 0 || start_y == 10 )

{

mouse_at_seat = false;

}

where_mouse(start_x,start_y);

gotoxy(start_x,start_y);

cout %26lt;%26lt; 'B' ;

}

what the program is meant to do is display an image of a plane(which it does!) and then by using the mouse you can click on any seat on the plane and book it, when a seat is booked 'B' will appear onthe seat.

unfortunately with my program you can click all over the plane and the letter 'b' will appear...

thats what the big long IF statement is there to prevent but its not working..

any ideas where have i went wrong?

C ++ problem?
You may contact a c++ helper live at website like

http://ccietutorial.com/
Reply:Hello

May I suggest the use of the ternary facility nested like this:

mouse_at_seat = (start_x %26lt; START_X + 2) ? false :

(start_x %26gt; START_X + ROWS * 2) ? false :

(start_y %26lt; START_Y + 2) ? false :

(start_y %26gt; START_Y + 10)? false :

(start_y - START_Y % 2!= 0) ? false :

(start_y == 10 ) ? false : true;

if (mouse_at_seat)

{

printf("TRUE\n");

}

else

{

printf("FALSE\n");

}

Using this you won't need the infinite loop

Regards

G
Reply:Isn't that an infinite loop? And if the if statement is true, you're still going to be in the loop. I think you need to put a condition in the loop or kill the for loop and move you if statement elsewhere.
Reply:Use parentheses in your if statement.

Not sure if it will fix the problem but it'll work better.

It should look like this:

if(

(start_x %26lt; (START_X + 2))

|| (start_x %26gt; (START_X + ROWS * 2))

||

etc...

C++ Coding problem?

2009-07-12T21:07:00.002-07:00

Can anyone suggest the error in this section of code? I am using vectors in a program for a phone book..... this function is to search for a person's phone number:

int search(const string%26amp; name, const vector%26lt;string%26gt;%26amp; nameList, const vector%26lt;int%26gt;%26amp; teleNumList)

{

vector%26lt;string%26gt;::iterator pos = find(nameList.begin(), nameList.end(), name);

int i = nameList(pos);

int Number = teleNumList[i];

return Number;

}

Anyone? Anyone? Bueller? Bueller?

C++ Coding problem?
Your problem is the line

int i = nameList(pos);

Because you want the index of the name you just found. But what that code does is it ends up retrieving the name itself, nit its index. And assigning the name to int i is meaningless, it is like assigning a string to an integer.

You need to convert the iterator pos to the index. The general way of doing that is

index = iter - cont.begin()

Applying that logic, your line becomes:

int i = pos - nameList.begin();

After that, the rest of the code should work.

One word of caution: when you search the name in the nameList, you should also check for the condition when the name was not found. The siplest way to do so is:

int search(const string%26amp; name, const vector%26lt;string%26gt;%26amp; nameList, const vector%26lt;int%26gt;%26amp; teleNumList)

{

vector%26lt;string%26gt;::iterator pos = find(nameList.begin(), nameList.end(), name);

if (pos != nameList.end())

{

int i = pos - nameList.begin();

if( (int) teleNumList.size() %26gt;= i + 1 )

return teleNumList[i];

else

{

cout %26lt;%26lt; "Phone list is shorter than name list." %26lt;%26lt; endl;

return -1; //or anything of your choice that denotes error

}

}

else

{

cout %26lt;%26lt; "Name not found." %26lt;%26lt; endl;

return -1; //or anything of your choice that denotes error

}

}
Reply:i think u r missing %26amp; reference operator before variables
Reply:Adamly, Anderson... Anderson? [HERE!]

Are you sure teleNumList contains actual telephone numbers? The teleNumList is defined as a vector of ints, but it's quite uncommon to represent phone numbers as ints --as they usually contain spaces, dashes and brackets...

[I deleted my unrelated suggestion, as it doesn't apply...]
Reply:Could not find the issue, may be you can contact a C++ expert at websites like http://oktutorial.com/

Help with my C++ program please!!! i am getting this error that i don't know how to fix:?

2009-07-12T21:07:00.001-07:00

cannot convert parameter 1 from 'const double' to 'double %26amp;'

this is my code:

#include%26lt;iostream%26gt;

#include %26lt;iomanip%26gt;

using std::cout;

using std::cin;

using std::endl;

using std::setprecision;

using std::fixed;

//fucntion prototype

void getInput(double %26amp;, double %26amp;, double %26amp;);

double calcAverage(double, double, double);

int main ()

{

//decalare variables

const double labAve = .50;

const double quizAve = .20;

const double examAve = .30;

double average = 0.0;

double getAverage = 0.0;

//enter functions to het input items

getInput(labAve, quizAve, examAve);

getAverage = calcAverage(labAve, quizAve, examAve);

//calculate and display average

cout %26lt;%26lt; fixed %26lt;%26lt; setprecision(2);

cout %26lt;%26lt;"Your average is : " %26lt;%26lt; average %26lt;%26lt; endl;

return 0;

} //end of main function

//**program defined functions ****

Help with my C++ program please!!! i am getting this error that i don't know how to fix:?
#include%26lt;iostream%26gt;

#include %26lt;iomanip%26gt;

using std::cout;

using std::cin;

using std::endl;

using std::setprecision;

using std::fixed;

//function prototype

void getInput(double %26amp;, double %26amp;, double %26amp;);

double calcAverage(double, double, double);

int main ()

{

//decalare variables

double labAve; // %26lt;- Removed const as you are putting values

double quizAve; // %26lt;- into these variables

double examAve; // %26lt;- If you not changing value, use const

double average; // %26lt;- Do not need a value assigned as it is assigned a value from a function call.

//enter functions to get input items

getInput(labAve, quizAve, examAve);

// calculate average of input and assign result to average.

average = calcAverage(labAve, quizAve, examAve);

//calculate and display average

cout %26lt;%26lt; fixed %26lt;%26lt; setprecision(2);

cout %26lt;%26lt;"Your average is : " %26lt;%26lt; average %26lt;%26lt; endl;

return 0;

} //end of main function

This should be what the code meant to do.

PS (To previous answerer). The joke was very funny.
Reply:%26amp; = address of

* = pointer to

double * ptr = %26amp;variable

you cannot define a function like

void function(double %26amp;ptr);

the correct way

void function(double *ptr);

learn C before you learn C++

one more thing remember to dereference your variables

cin %26gt;%26gt; *ptr;
Reply:No you can't. Use const when you can declare a variable at initialization and will not touch it otherwise. Yes I know there are supposed to be specialized cases where you can change it but DON'T. Take that filthy const out of the declaration of the variables YOU WANT TO INPUT. And while you are at it, since you send calcAverage into getAverage try printing it rather than average (which you do after having initialized it to zero and done nothing else).

Okay. I don't like const so I try to avoid it (#define is better) but I'll give you a hint. There is actually, in C++ a difference between passing the address of a variable and passing a pointer to that variable. I'm not saying you can't do it, I'm just saying the preprocessor can tell the difference between an address of something and a pointer to something.

Just remember:

" In C, you merely shoot yourself in the foot.

" In C++, you accidentally create a dozen instances of yourself and shoot them all in the foot. Providing emergency medical care is impossible, because you can't tell which are bitwise copies and which are just pointing at others and saying, "That's me, over there." "

--old UseNet joke.

A college senior crushing on a const worker - part2?

2009-07-12T21:07:00.000-07:00

I have had a crush on a construction worker at school. We sort of flirted, but not to an extreme degree. I dont even know his last name. we're both shy. Anyhow, he disappeared for 2 months, i asked his friend and, his friend said that my crush's coming back and if i wanna leave him a msg and i said that its ok. Finally he came back! the first day he came back, his friend was like, John's back, he's over there if you wanna talk to him. But I didn't b/c I didnt want to creep him out/terrified. I kinda expected he'd come to my lab to say g'bye like he used to before he disappeared, but he didnt! I really dont run into him a lot anymore. I see him from distance, we still say hi from really far away (wave hands). Its been 4 days since he's been back. Why wouldnt he drift away from his work and come talk to me? Does that mean hes not interested in flirting anymore? Or was it bad that I didnt go talk to him the first day he came back? I didnt want to appear as a desperate fool!

A college senior crushing on a const worker - part2?
I think he thinks you are not interested in him anymore and he is trying to move on but still thinks about you. Try talking to him it might be already to late

survey research

Help with c programming?

2009-07-12T21:06:00.003-07:00

I am working on a program that i need the user to input two lines of text. The first longer then the second. The program is supposed to count how many times the second line appears in the first line. I am almost done. I am having trouble testing if line 2 is in line1 because it must be case and space sensitive . if anyone has examples or any suggestions i would appreciate it. thnx

int strstrcnt(const char *s1, const char *s2, int j)

{

int count;

char * strstr(const char *s1, const char *s2);

char *k;

/*for(j=0; j%26lt;s1size; j++)*/

k = strstr(s1,s2), count++;

return(k);

}

This is a sample of my code can anyone help. I have the part where the program asks the user i just need help with this function to count the number of occurrences. thnx

Help with c programming?
As you realise, the strstr() function is the right choice. You need to test the return value from strstr() and if not null, increase your counter, and test for another occurance of the smaller string until it does not find one.

The trick to use a pointer that initially points to the start of the large string, and is bumpped up for each successive call.

Something like this should be close to what you need.

int count( char *large, char *small )

{

char *cp; /* pointer at what to give to strstr */

char *nxt; /* pointer at next occurance of little */

int slen; /* length of little string */

int count = 0;

slen = strlen( small );

cp = large;

while( strlen(cp) %26gt; slen %26amp;%26amp; (nxt = strstr( cp, small )) != NULL )

{

count++;

cp = nxt + slen; /* skip over last match */

}

return count;

}
Reply:Instead of coding it for you, I'll suggest an approach.

L1 = length(s1);

L2 = length(s2);

for (i = 0; i %26lt; ((L1 - L2); i++)

create s3, which is length L2, starting from s1[i]

compare and count

CAN ANYBODY CHECK MY C++ PROGRAM WHAT's wrong with it?

2009-07-12T21:06:00.002-07:00

#include %26lt;iostream%26gt;

using namespace std;

void matrix_Multi(const int*matA,const int*matB,const int*matC,int m,int n,int l);

void printArray2(double*,int %26amp;nRow,int %26amp;ncol);

void readArray2( double *, int %26amp;nRow, int %26amp;nCol );

int main()

{

double m,n,l,i,j;

char x;

double *ArrayA,*ArrayB,*ArrayC;

char choice;

do{

std::cout %26lt;%26lt; "Matrix multiplication (A*B):" %26lt;%26lt; std::endl;

std::cout %26lt;%26lt; "Enter the dimension of matrix" %26lt;%26lt; std::endl;

std::cout %26lt;%26lt; "A:";

cin%26gt;%26gt;m;

cout%26lt;%26lt;m;

cin%26gt;%26gt;x;

cout%26lt;%26lt;x;

cin%26gt;%26gt;n;

cout%26lt;%26lt;n%26lt;%26lt; std::endl;

ArrayA=new double*m*n;

readArray2(ArrayA,m,n);

std::cout %26lt;%26lt; "Enter the dimension of matrix" %26lt;%26lt; std::endl;

std::cout %26lt;%26lt; "B:"%26lt;%26lt;n%26lt;%26lt;"x ";

cin%26gt;%26gt;l;

cout%26lt;%26lt;l;

ArrayB=new double*n*l;

readArray2(ArrayB,n,l);

ArrayC=new double*m*l;

matrix_Multi(ArrayA,ArrayB, ArrayC,m,n,l);

printArray2(ArrayC,m,l);

std::cout%26lt;%26lt;"Process another matrix multiplication or Quit(P/Q):";

cin%26gt;%26gt;choice;

cout%26lt;%26lt;choice;

}while(choice=='p'||choice=='P');

return 0;

}

void readArray2( double *Array, int %26amp;nRow, int %26amp;nCol)

{

int i,j;

cout%26lt;%26lt;"Enter elements of A row by row ("%26lt;%26lt;nCol%26lt;%26lt;" elements per row):"%26lt;%26lt;endl;

for(i=0;i%26lt;nRow;i++){

cout%26lt;%26lt;"Row "%26lt;%26lt;i+1%26lt;%26lt;" "\n";

for(j=0;j%26lt;nCol;j++){

cin%26gt;%26gt;Array[i*nCol+j];

}

while(getchar()!='\n');

}

}

void printArray2(double *Array,int %26amp;nRow,int %26amp;ncol)

{

int i,j;

for(i=0;i%26lt;nRow;i++){

for(j=0;j%26lt;nCol;j++){

cout%26lt;%26lt;Array[i*nCol+j]%26lt;%26lt;"\t";

}

cout%26lt;%26lt;"\n";

}

}

void matrix_Multi(const int *matA, const int *matB, int *matC, int m, int n, int l)

{

int i,cm,cl;

for(cm=0;cm%26lt;m;cm++){

for(cl=0;cl%26lt;l;cl++){

matC[cm*l+cl]=0;

for(i=0;i%26lt;n;i++){

matC[cm*l+cl]+=matA[cm*n+i]*matB[i*l+cl]...

}

}

}

}

CAN ANYBODY CHECK MY C++ PROGRAM WHAT's wrong with it?
I don't know how you got your sample run because the code you posted have a lot of compilations errors.

I fixed them, but since some of the line of your code got cutted by YA I can't really check the result.

Anyway here it is :

#include "stdafx.h"

#include %26lt;iostream%26gt;

using namespace std;

void readArray2( double* Array, int%26amp; nRow, int%26amp; nCol);

void matrix_Multi(const double *matA, const double *matB,

double *matC, int m, int n, int l);

void printArray2(double *Array,int %26amp;nRow,int %26amp;ncol);

int main()

{

int a1,a2;

int b2;

char x;

double *ArrayA,*ArrayB,*ArrayC;

char choice;

do

{

std::cout %26lt;%26lt; "Matrix multiplication (A*B):" %26lt;%26lt; std::endl;

std::cout %26lt;%26lt; "Enter the dimension of matrix" %26lt;%26lt; std::endl;

std::cout %26lt;%26lt; "A:";

cin%26gt;%26gt;a1;

cout%26lt;%26lt;a1;

cin%26gt;%26gt;x;

cout%26lt;%26lt;x;

cin%26gt;%26gt;a2;

cout %26lt;%26lt;a2 %26lt;%26lt; std::endl;

ArrayA =new double[a1*a2];

readArray2(ArrayA,a1,a2);

std::cout %26lt;%26lt; "Enter the dimension of matrix" %26lt;%26lt; std::endl;

std::cout %26lt;%26lt; "B:"%26lt;%26lt; a1 %26lt;%26lt;"x ";

cin%26gt;%26gt; b2;

cout%26lt;%26lt; b2;

ArrayB=new double[a2*b2];

readArray2(ArrayB,a2,b2);

ArrayC=new double[a1*b2];

matrix_Multi(ArrayA,ArrayB, ArrayC,a1,a2,b2);

printArray2(ArrayC,a2,b2);

std::cout%26lt;%26lt;"Process another matrix multiplication or Quit(P/Q):";

cin%26gt;%26gt;choice;

cout%26lt;%26lt;choice;

} while (choice=='p'|| choice=='P');

return 0;

}

void readArray2( double *Array, int %26amp;nRow, int %26amp;nCol)

{

int i,j;

cout%26lt;%26lt;"Enter elements of A row by row ("

%26lt;%26lt;nCol%26lt;%26lt;" elements per row):"%26lt;%26lt;endl;

for(i=0;i%26lt;nRow;i++)

{

cout %26lt;%26lt; "Row " %26lt;%26lt; i+1 %26lt;%26lt; "\n";

for(j=0;j%26lt;nCol;j++)

{

cin%26gt;%26gt;Array[i*nCol+j];

}

while(getchar()!='\n');

}

}

void printArray2(double *Array,int %26amp;nRow,int %26amp;ncol)

{

int i,j;

for(i=0;i%26lt;nRow;i++)

{

for(j=0;j%26lt;ncol;j++)

{

cout%26lt;%26lt;Array[i*ncol+j]%26lt;%26lt;"\t";

}

cout%26lt;%26lt;"\n";

}

}

void matrix_Multi(const double *matA, const double *matB,

double *matC, int m, int n, int l)

{

int i,cm,cl;

for(cm=0;cm%26lt;m;cm++)

{

for(cl=0;cl%26lt;l;cl++)

{

matC[cm*l+cl]=0;

for(i=0;i%26lt;n;i++)

{

matC[cm*l+cl] += matA[cm*n+i] ; // end of line missing

}

}

}

}
Reply:what is it doing or showing that tells you that something is wrong? are you getting a compiling error, runtime, or just an incorrect answer?

C++ help please?

2009-07-12T21:06:00.001-07:00

would anybody be able to help me with this?

bool isReflexive (const int mat[N][N], int size) {

// ????????????????????????

return 0; // fix return

}

// returns whether or not a Matrix is Symmetric

bool isSymmetric (const int mat[N][N], int size) {

// ????????????????????????

return 0; // fix return

}

// returns whether or not a Matrix is Transitive

bool isTransitive (const int mat[N][N], int size) {

// ????????????????????????

return 0; // fix return

}

// returns whether or not a Matrix is an Equivalence Relation

bool isEquivalenceRelation (const int mat[N][N], int size) {

// ????????????????????????

return 0; // fix return

}

C++ help please?
this would be easier to answer if you provided the formulas for each function... for example:

symmetric matrix:

aij = aji

then we can use this lines for the isSymmetric function:

bool isSymmetric (const int mat[N][N], int size) {

int i, j;

for(i=0;i%26lt;=size;i++ {

for(j=0;%26lt;=size;j++) {

if(mat[i][j] != mat[j][i]) {

return 0;

}

}

}

return 1;

}

this code checks every value inside our mat[][] array if the condition aij = aji is satisfied if it is.. we will return 1 if at least 1 of the values inside of mat[][] does not conform to the condition then we return 0

please show the conditions for reflexive, transitive and equivalence... but basing from the code above i think you can make your own algorithm for the other functions :D

good luck
Reply:You may contact a C++ helper live at website like

http://gionram.com/

Can someone change this c++ program into another c language like (printf,scanf) this is calendar program?

2009-07-12T21:06:00.000-07:00

#include %26lt;iostream%26gt;

#include %26lt;iomanip%26gt;

#include %26lt;string%26gt;

#include %26lt;cctype%26gt;

#include %26lt;ctime%26gt;

#include %26lt;cstdlib%26gt;

using namespace std;

// true if s1 is a prefix of s2, not case sensitive

bool prefix(const string%26amp; s1, const char* s2) {

for (int i=0;; ++i) {

if (i==int(s1.size()))

return true;

if (s2[i]==0 || tolower(s1[i])!=tolower(s2[i]))

return false;

}

}

// A Month represents a month and year, which prints as a calendar

class Month {

public:

Month(const string%26amp; m="", int y=0); // Defaults: this month and year

// m is the month name or prefix, not case sensitive

class Ambiguous {}; // Thrown if m matches %26gt;1 month name, e.g. "JU"

class Invalid {}; // Thrown if m matches no month name, e.g. "X"

void print(ostream%26amp; out) const; // Print a one month calendar to out

void add(int n) {now+=n;} // Add n months (may be negative)

private:

int now; // year * 12 + month (0=Jan, 11=Dec), e.g. 24001 means Feb. 2000

static con

Can someone change this c++ program into another c language like (printf,scanf) this is calendar program?
have u tried it yet

first try it urself and post the errors then after we will help ya
Reply:Yes, you may contact a C expert to convert it. Check websites like http://oktutorial.com/
Reply:its_tru_its_damm is right, first of all - you help yourself then ask from others.

survey for money

C++ user defined arrays?

2009-07-12T21:05:00.002-07:00

Ok, last week my problem was getting two 3x3 matrices (whose elements were defined by the user) multiplied, and thanks to the help from here I got it figured out. This week, we're just supposed to stretch this out a bit, by letting the user state the size of his matrices. I thought it would be as simple as removing the 3 from:

const int row = 3;

const int column =3;

and just using a cin to let the user define these variables, but this small change spat back 22 errors at me. I take it you can't do this with an array, but then how do you let a user define it's size?

a snippit:

int main( )

{

const int row;

const int column;

int i, j;

cout %26lt;%26lt;"How many rows will this matrix have?" %26lt;%26lt; endl;

cin%26gt;%26gt;row;

cout %26lt;%26lt;"How many columns will this matrix have?" %26lt;%26lt; endl;

cin%26gt;%26gt;column;

cout %26lt;%26lt; "FIRST MATRIX (A):" %26lt;%26lt; endl;

for (i = 0; i %26lt; row; i++)

for (j = 0; j %26lt; column; j++)

{

cout %26lt;%26lt; "Enter value for row " %26lt;%26lt; i+1 %26lt;%26lt; " column " %26lt;%26lt; j+1 %26lt;%26lt; ": " %26lt;%26lt; endl;

cin %26gt;%26gt; matrixOne[i][j];

.

.

.

C++ user defined arrays?
Something like this should do

int main( )

{

int row;

int column;

int i, j;

cout %26lt;%26lt;"How many rows will this matrix have?" %26lt;%26lt; endl;

cin%26gt;%26gt;row;

cout %26lt;%26lt;"How many columns will this matrix have?" %26lt;%26lt; endl;

cin%26gt;%26gt;column;

int matrix[row][column];
Reply:You can't cin %26gt;%26gt; row; or cin %26gt;%26gt; column; if it defined as a const.

Remove "const" before int row and int column and it should start working.

...................c++?

2009-07-12T21:05:00.001-07:00

How would I create a program that that displays the sum of a sales amount in each of 4 regions, during a 3 month period, which would also display the sum? …Nothing fancy. I am a beginner and want to be able to understand the code…Pls…

I need to loop it …this is what I have but I am terrible wrong I am sure. There has to be a way off not adding all the regions? I commented out some of the region.

include %26lt;iostream%26gt;

using std::cout;

using std::cin;

using std::endl;

int main()

{ double sales = 0.0;

double totalSales = 0.0;

int region = 0;

const int Nregion = 1;

const int Sregion = 2;

const int Eregion = 3;

const int Wregion = 4;

while (region %26lt; 4)

{

cout%26lt;%26lt; "Enter first sale amount for North region " %26lt;%26lt; Nregion %26lt;%26lt; " : " ;

cin %26gt;%26gt; sales;

//cout%26lt;%26lt; "Enter first sale amount for South region " %26lt;%26lt; Sregion %26lt;%26lt; " : " ;

//cin %26gt;%26gt; sales;

{

totalSales = totalSales + sales;

// cout%26lt;%26lt; "Enter next sale amount region " %26lt;%26lt; region %26lt;%26lt; " :" ;

//cin %26gt;%26gt; sales;

}

cout %26lt;%26lt; "Region" %26lt;%26lt; region %26lt;%26lt; "sales: "

%26lt;%26lt; totalSales %26lt;%26lt; endl;

region = region + 1;

totalSales = 0.0;

Return 0;

}

...................c++?
Try to understand logic and problem solving using programming languages and then object oriented concept. Then it comes to C++. By the way , i have sited (good approach) an example for your problem :-

#include %26lt;iostream%26gt;

#include %26lt;string%26gt;

using namespace std;

class regions{

string regionName;

int sale;

public:

regions(){}

public:

void setRegionName(string rname){

regionName = rname;

}

void setRegionSale(int s){

sale = s;

}

void showRegionInfo(){

cout%26lt;%26lt;"\n Region Name :"%26lt;%26lt;regionName%26lt;%26lt;" ; \n "%26lt;%26lt; "Sale : "%26lt;%26lt;sale%26lt;%26lt;"\n";

}

string getName(){

return regionName;

}

int getSale(){

return sale;

}

regions operator+(regions r){

regions r1;

r1.setRegionName(regionName + ", " + r.getName());

r1.setRegionSale(sale + r.getSale());

return r1;

}

};

int main() {

regions n,s,e,w;

n.setRegionName("North Reg");

s.setRegionName("South Reg");

e.setRegionName("East Reg");

w.setRegionName("West Reg");

n.setRegionSale(1000);

s.setRegionSale(1400);

e.setRegionSale(1100);

w.setRegionSale(1200);

regions combinedRegion = n+e+s+w;

combinedRegion.showRegionInfo();

return 0;

}
Reply:were you taught about structures / multi dimensional arrays ;-)

thats a hint...

I'm not gonna do ya homework for ya.

Help with an C++ homework question.?

2009-07-12T21:05:00.000-07:00

i'm having problems creating and implementing the final requirment:void remove_message(int i) const;

This is my question:

You have to create a class called mailbox. You don't yet know how to store a collection of message objects. Instead, use the following brute force approach: The mailbox contains one very long string, which is the concatenation of all messages. You can tell where a new message starts by searching for a From: at the beginning of a line. This may sound like a dumb strategy, but surprisingly, many e-mail systems do just that.

Implement the following member functions:

void Mailbox::add_message(Message m);

Message Mailbox::get_message(int i) const;

void remove_message(int i) const;

I would appreciate any input or comments anyone can make about what I have so far and if what I am doing or trying to do makes sense.

class Mailbox

{

public:

Mailbox(string u);

void add_message(Message m);

Message get_message(int i) const;

int count_messages() const;

string get_user() const;

private:

vector%26lt;Message%26gt; messages;

string user;

};

Mailbox::Mailbox(string u)

{

user = u;

}

string Mailbox::get_user() const

{

return user;

}

void Mailbox::add_message(Message m)

{

messages.push_back(m);

}

Message Mailbox::get_message(int message_num) const

{

return messages[message_num];

}

int Mailbox::count_messages() const

{

return messages.size();

}

Help with an C++ homework question.?
The first problem with this is that you say you want to implement the function:

void remove_message(int i) const

This doesn't make sense, since only member functions can be declared const. Global functions can never be declared const. I assume you meant:

void Mailbox::remove_message(int i) const

The problem with this is that if this function is meant to effectively delete some data from the Mailbox class, then it is not legally allowed to do so because the function is declared as being const, which means it is not allowed to alter any members of the class of which it is itself a member.

However, the following would be legal:

void Mailbox::remove_message(int i)

In order to implement this in your version of the Mailbox class you would do:

void Mailbox::remove_message(int i)

{

messages.erase( members.begin() + i );

// Your compiler might not like the members.begin() + i.

// If this is the case use the following code instead

// std::vector%26lt; Message %26gt;::iterator itr;

// for ( int iCount = 0; iCount %26lt; i; iCount++ )

// {

// ++itr;

// }

// messages.erase( itr );

}

While your approach would work, it's not what you've been asked to do. The question states:

"You don't yet know how to store a collection of message objects. Instead, use the following brute force approach: The mailbox contains one very long string, which is the concatenation of all messages. You can tell where a new message starts by searching for a From: at the beginning of a line."

This means you shouldn't be using a member vector to store the messages. Instead you should be using a single very long string member to store all the messages, which you then parse to find a particular message. Basically, all the code you have to write is a bunch of string manipulation functions. I suggest you use a STL string object rather than a C style char array as this means you don't have to have a maximum string length for your storage string when you declare it nor do you have to manage the string's internal memory allocation yourself.

As you haven't included any details about the Message class I can't tell how you extract a string from a Message. Is Message a class/struct that has a string member, or is it just a typedef to std::string?

Help with an C++ assignment question.?

2009-07-12T21:04:00.003-07:00

A college senior crushing on a const worker?

2009-07-12T21:04:00.002-07:00

I am a senior in college, and I have had a mega crush on this construction worker at my school. We kind of flirted. We exchanged eye contact a lot, started saying hi, and finally we talked. It's weird, because I am 21 and I am guessing he's like 25, and the whole flirting was totally like junior high (lots of giggling of friends involved). Well, the thing is, in me and my friends' opinion, the flirting was at its peak, but one day he disappeared. Right before he left though, I was on the other side of the building studying, and he and his friend kept looking at my direction discussing something fervently. I am thinking maybe he was debating whether he should say good bye maybe b/c he was being moved to another site? He's been gone for 2 weeks ever since, but his friend is still here. Long union vacation? Army reserve? I feel like he won't come back... Is it super creepy if I give his friend my number? I have never talked to his friend, but he sorta smiled a lot when I ran into my crush

A college senior crushing on a const worker?
I am a Project Manager/Engineer for a construction company, we recently had a project going at a large college. I had a particular field guy who was continuously batting eyes at all of the girls. I had to fire him. He had been getting little to no work done and the owners rep (college dean) had complained about him.

Chances are that if you noticed him looking and his co workers noticed, the owners rep (ie college dean) noticed as well and complained which may mean your romeo is unemployed (as was the fate of the young man formerly in my employ) right now. Do you WANT to date an unemployed 20 something? Didn't think so. Forget about the guy, he is long gone and has other things on his mind by now.
Reply:I would go ask casaually what happened to the other guy. But under no circumsances should you give out personal information that could lead to where you live.
Reply:maybe hes just a tough dude. or maybe he has a gf. or maybe he flirts with many girls at all different places coz the nature of his job. i would say get over him.
Reply:Yes. It sounds like is is shy but pretty into you.

C++ "=" operator overloading?

2009-07-12T21:04:00.001-07:00

I have following class, I want to overload “=” operator, I did as following but I cant get success, any one can help me please

class String

{

private:

char * name;

public:

const char * getName() const { }

void setName(const char * aname) { }

friend char * operator=(char %26amp; str, const String %26amp;rhs );

}

char * operator= (char %26amp;str, const String %26amp;rhs )

{

str = const_cast%26lt;char * %26gt;(rhs.getName())

return *str;

}

Void main()

{

String obj;

Obj.setName(“Hello World “);

Char * myString = Obj;

Cout%26lt;%26lt;myString;

}

C++ "=" operator overloading?
Sure.

Your problem here is that the parameters for your operator = are (char %26amp;, String %26amp;). You have two problems here.

First, you want to make that char *%26amp;, not char %26amp;. As defined here, you have an operator = that copies a string into a single character.

The second problem is a little bigger. You are copying a pointer here instead of doing any sort of copying of contents. When done, myString wand Obj will point at the SAME string.

While this makes for a very fast copy, you're almost guaranteed to have problems later:

1. Notice what happens to myString when Obj is deleted. myString is now pointing at deleted memory. The reverse is true as well.

2. If myString changes, so does Obj. The reverse is true as well.

3. There is no safe way to destroy the name * in your string object because you don't know how many copies were made, and if those are still in use. I'm assuming here that the implementation of setName() will allocate new memory for name, and that your full version has a destructor.

I hope this helps. Good luck.
Reply:You have completely mixed your metaphors here.

First off, your operator = only needs to take one parameter, not two -- and that parameter is whatever type you want to be able to assign TO your String.

Second, your operator = should return a String%26amp;.

Third, in order to assign a String object to a char*, you need to overload the char* cast operator.

And finally, make sure you understand that char* is just a pointer -- to actually put anything IN your string, you're going to have to dynamically allocate memory.

Cant figure out whats wrong C++?

2009-07-12T21:04:00.000-07:00

//Class declaration for the rectangle class

class house

{

public:

//default constructor

house():

house(double l, double w, double h, double R_wall, double R_ceiling, double in_temp, double out_temp);

//accesor funtions

double get_length() const;

double get_width() const;

double get_height() const;

double get_R_walls() const;

double get_R_ceilings() const;

double get_in_temp() const;

double get_out_temp() const;

//function for input and output.

double input(istream%26amp; in);

double output(ostream%26amp; out) const;

//additional member function prototypes.

void set_value(double l, double w, double h, double R_wall, double R_ceiling, double in_temp, double out_temp);

double area() const;

private:

//declaration of data members;

double length, width, height, R_walls, R_ceilings, in_temp, out_temp;

};

#endif

#include %26lt;iostream%26gt;

using namespace std;

using :: istream;

using :: ostream;

house:house(double l, double w, double h, double R_wall, double R_ceiling, double in_temp, double out_temp);

length(l), width(w), height(h), R_walls(R_wall), R_ceilings(R_ceiling), in_temp(in_temp), out_temp(out_temp);

{

}

void house::set_value(double l, double w, double h, double R_wall, double R_ceiling, double in_temp, double out_temp)

{

//set the value of the calling object.

length = l;

width = w;

height = h;

R_walls = R_wall ;

R_ceilings = R_ceiling;

in_temp = in_temp;

out_temp = out_temp;

return;

}

Cant figure out whats wrong C++?
1.)

When you declare house::house(), you should write "house();" not "house:". Using a colon instead of a semicolon makes the compiler expect to see an initialization list.

2.)

When you define house::house(), you should write "house::house", not "house:house", because "house::house" is the fully-qualified name of the function, whereas "house:house" is simply an illegal construct.

3.)

When you give an initialization list for house::house, you should not terminate the initialization list in a semicolon. The initialization list is terminated by the open brace.

4.)

You appear to be missing the definitions of a number of other functions.

5.)

You should define a copy constructor "house::house(const house%26amp;)", and then you can simply use the default assignment operator instead of set_value.

Say me the physical meaning of time const.?

2009-07-12T21:03:00.003-07:00

Time constant of a low pass or high pass R-C circuit is ofcourse the product of R and C. but what it exactly do during circuit functioning?

Say me the physical meaning of time const.?
Suppose an electronic circuit is made of resistor, capacitor and with other elements, and we shall apply an input electrical signal to the circuit's input terminal. We expect that the signal at the output must change at the same time in synchronism to the input signal. Due to RC time constant, the response of the circuit-output will take some time. Ideally there should not be any time delay between the change of input and output signals. Thus RC time constant puts a limit on how fast input signal it can handle.
Reply:the easiest way to understant it is to present your low-pass circuit with a 0 1 signal.

When the input is 0, the output is 0.

The input changes to 1, the output stays 0 for a time, because the capacitor needs times to charge... it will take a time of about RC to get to 1...

that's the meaning of this time constant.

you can then easily understand that if you present your low pass filter with a signal of frequency %26gt; 1/RC, then it won't have enough time to shift to 1 before the input signal shifts back to 0... and the output signal will be a faded version of the input signal...

------------------

in the case of a high pass filter, you want to have a variation of tension fast enough not to charge/discharge your capacitor, or all the tension would be located on the capacitor.

If you give enough time for the capacitor of a high pass filter to charge/discharge, then a differential of charge will appear in the capacitor and the input tension will be spent exclusively on the capacitor and not on the resistor... therefore, the output signal will be 0.

also: R and C are important in this constant, because the current will be proportional to R and it takes a duration proportional to C to charge a capacitor with a given current.

surveys

Wat is the diff b/w const char* p and char const *p?

2009-07-12T21:03:00.002-07:00

I have doubt in C programming language.

Wat is the diff b/w const char* p and char const *p?
There is no functional difference. Its all just preference. Some people like to designate that a pointer is being used beside the data type, and others prefer to signify a point beside the variable name. Placement of "const" shouldn't matter either.

Notice that there is no functional difference in the outputs:

#include %26lt;iostream%26gt;

using namespace std;

int main(){

char d='a';

const char* c=%26amp;d;

char const *b=%26amp;d;

cout%26lt;%26lt;c%26lt;%26lt;endl;

cout%26lt;%26lt;b%26lt;%26lt;endl;

//Require for Dev-C++

//system("pause");

return 0;

}

What is the differnce between " const char * " and " char * const "?

2009-07-12T21:03:00.001-07:00

In C Programming, What is the most efficient way to count the number of bits which are set in a value?

What is the differnce between " const char * " and " char * const "?
There is no difference between

const char *

and

char const *

They are both pointers to constant chars. It is merely a style preference on which one to use,

The third variation would be

char * const

This is different than the first 2, This is a constant pointer.

With the first 2, you can make the pointer point to any char variable, but you can't change that variable's value.

eg

char x,y;

const char * p = %26amp;x;

p = y; //legal

*p = 'a'; //illegal

A constant pointer is the opposite. You can only set the pointer location at declaration time, but you can dereference and change the value. eg

char x,y;

char * const p = %26amp;x;

*p = 'a'; //legal

p = %26amp;y ;// illegal

As for counting the number of bits set. I'm with Scottso. I usually just use bit shifts.
Reply:1: i dont beleive there is a difference (not sure)

2: i use bitshift and mod by 2, idk if it is most efficient tho

What could I do to copy a string into a multiple array string in c++?

2009-07-12T21:03:00.000-07:00

I am writing a program in c++, I would like to copy a srting into a multiple array string. i have used the srtcpy() function but Iam getting an error message telling me that :

-invalid conversion from 'char' to 'char*'

-initializing argument 1 of 'char*' strcpy(char*, const char*).

//this is what I get as message. and here is my program:

# include%26lt;iostream%26gt;

#include%26lt;string%26gt;

using namespace std;

int main()

{int namsize;

char names[20][20], newname[18] ;

cout%26lt;%26lt;"what is the size of your name";

cin%26gt;%26gt;namsize;

cout%26lt;%26lt;" please enter the name";

cin.getline(newname,namsize);

for (int i=0;i%26lt;=(namsize+1);i++)

strcpy(names[i][1],newname[i]);

system("pause");

return 0;

}

please could you help me to solve this problem? thanks

What could I do to copy a string into a multiple array string in c++?
do strcpy(names[i],newname) instead of

strcpy(names[i][1],newname[i])

and the for loop should go from 0 to 19.

for (int i=0;i%26lt;20;i++)

strcpy(names[i],newname);

( i am assuming you want to create 20 copies of the same name in the array)

strcpy has the loop built into it. you just need to pass the pointer to the char array to it ,terminated by null of course.(If u din get the last part, its ok)
Reply:this is a syntax error! you need spaces between char names [20] [20]..that should work!
Reply:/*

just do copy of one string onto the next

eg. shown below is a c++ code

*/

# include%26lt;iostream%26gt;

#include%26lt;string%26gt;

using namespace std;

int main()

{

int namsize;

string names="fanda", newname ;

newname=names;

cout %26lt;%26lt;"\nnames: "%26lt;%26lt;names;

cout%26lt;%26lt;"\nnewname: "%26lt;%26lt;newname;

cout%26lt;%26lt;endl;

system("pause");

return 0;

}
Reply:You are using C++. Seriously consider using std::vector and std::string. Then you don't have to ask really odd questions like "what is the size of your name".

Also consider joining a YahooGroup for C/C++ programming instead of using Yahoo Answers for questions like this. You'll learn a LOT more that way by being part of a community who shares the same interests and goals.

HELP!! Lost on homework C++ (dogsafire)?

2009-07-12T21:02:00.003-07:00

dogsafire,

I haven't got far. We just got this and didn't get much info. I am in a C++ programing class and the teacher just reads from power point. Last semester only two people passed, now I see why.

I have the highest score in the class and stll don't know what the heck I am doing till we are about 3 weeks past it.

This is our first assn in arrays, we are using Walter Savitch's 6th Edition. I am just trying to get started on this prob. I am having a hard time understanding how to translate the prob into:

const int MAX = 10;

void outputA (int a[], int size);

int main () {

int a[MAX];

int i;

int x;

for (i=0;i%26lt;MAX;i++)

a[i]=0;

cout %26lt;%26lt; "Input grades ending with -1 "; // Has to be an int for this situation like(-1)

cin %26gt;%26gt; x;

i = 0;

while (x%26gt;=0 %26amp;%26amp; i%26lt;MAX){

a[i] = x;

i++;

cout %26lt;%26lt; "next: ";

cin %26gt;%26gt; x;}

for (i=0;i%26lt;MAX;i++)

cout %26lt;%26lt; a[i] %26lt;%26lt; endl;return 0;

outputA(a,i);

}

void outputA (int a[], int size){

int i;

for (i=0;i%26lt;size;i++)

cout %26lt;%26lt; a[i] %26lt;%26lt; endl;

}

HELP!! Lost on homework C++ (dogsafire)?
If you are still stuck with your homework may be you can post it at homework help website like http://homeworkhelp.co.in/ .
Reply:Your code isn't bad, you don't appear to be lost. My comments are inlined below. Is there something in particular you're confused about?

const int MAX = 10;

// void outputA (int a[], int size);

// recommend const pointer, const data for int[] arg

void outputA(const int * const, int);

int main () {

int a[MAX] = {0}; // see comment below

int i;

int x;

#if 0

for (i=0;i%26lt;MAX;i++) // don't need this...

a[i]=0; // init on declaration (above)

#endif

cout %26lt;%26lt; "Input grades ending with -1: ";

cin %26gt;%26gt; x;

i = 0;

#if 0

while (x%26gt;=0 %26amp;%26amp; i%26lt;MAX){

a[i] = x;

i++;

cout %26lt;%26lt; "next: ";

cin %26gt;%26gt; x;

}

#else

// do something like this so you don't

// get the prompt for grade MAX+1

while (x %26gt;= 0) {

a[i++] = x;

if (i == MAX) break;

cout %26lt;%26lt; "next: ";

cin %26gt;%26gt; x;

}

#endif

#if 0

for (i=0;i%26lt;MAX;i++) // after this loop i=10, so

cout %26lt;%26lt; a[i] %26lt;%26lt; endl; // the call to outputA will

// return 0; ??? // print it all again

#endif

outputA(a,i);

}

// void outputA (int a[], int size){

void outputA(const int * const a, int size){

int i;

for (i=0;i%26lt;size;i++)

cout %26lt;%26lt; a[i] %26lt;%26lt; endl;

}

survey monkey

Why can't I compile this Linux C++ code?

2009-07-12T21:02:00.002-07:00

I've almost fixed all of the outdated code in an old Linux program coded in C++. However I keep getting the following error when I try to compile it.

no match for 'operator%26lt;%26lt;' in 'std::cout %26lt;%26lt; str'

It happens on a few lines of code

void TServerFrame::tolog(const JString%26amp; str) {

JString filename = getDir()+"log/rclog.txt";

ofstream out(filename.text(),ios::out | ios::app);

if (out) {

time_t t = time(NULL);

out %26lt;%26lt; "Time: " %26lt;%26lt; ctime(%26amp;t);

out %26lt;%26lt; str %26lt;%26lt; endl; %26lt;------------here

out.close();

}

}

void TServerFrame::toerrorlog(JString str) {

time_t t = time(NULL);

str = JString() + "Time: " + ctime(%26amp;t) + str + "\n";

cout %26lt;%26lt; str; %26lt;----- here

JString filename = getDir()+"errorlog.txt";

ofstream out(filename.text(),ios::out | ios::app);

if (out) {

out %26lt;%26lt; str; %26lt;--------and here

out.close();

}

}

Can anyone help me?

Why can't I compile this Linux C++ code?
The problem is that cout and cin don't know squat about Jstrings.

Does Jstring have a member function that returns, say, a c++ "string" type?

Or a member function that returns a normal, null-terminated c-type string?

Does Jstring have a member func. like c_str() (similar to the STL string type)?

This is where your problem lies.

Can someone help me with C++ programming?

2009-07-12T21:02:00.001-07:00

I need the program to have 3 options. Choose how many #'s to enter, and display the largest # input; enter #'s until -99 is input then end program and display smallest # entered; or quit the program. I have a large part of the program written but it's not working properly and I am pretty new to programming. Can someone just help me get the code for the first part straightened out then maybe I can figure it out from there. Here is what I have:

#include %26lt;iostream%26gt;

using namespace std;

const int SENTINEL = -99; //to end option 'B'

int number; //variable to store #s

int counter;

char limit; //variable to store amount of #s to input in 'A'

int main()

{char sel;

number = 0;

int count = 0;

do{

cout %26lt;%26lt; "A) Find the largest # in a list." %26lt;%26lt; endl;

cout %26lt;%26lt; "B) Find the smallest # in a list." %26lt;%26lt; endl;

cout %26lt;%26lt; "C) Quit." %26lt;%26lt; endl;

cout %26lt;%26lt; "What do you want to do?" %26lt;%26lt; endl;

cin %26gt;%26gt; sel;

switch (sel)

{case 'A':

case 'a':

cout %26lt;%26lt; "Enter the amount of numbers to input in series: ";

Can someone help me with C++ programming?
cin %26gt;%26gt; limit;

limit needs to be converted from an ascii letter '3' to an integer.

trick could be limit = limit - '0'

or do it the proper way
Reply:instead of initializing count to 0, initialize it to 1. now count will start at 1. or you could put the count++ before your cout statement.

the other person could be right about limit being in ASCII. set a breakpoint after the cin %26gt;%26gt; limit; line, and see what value you have in limit. if its 0x30 - 0x39 when you enter a 0 - 9 then its ASCII. you could make your while statement read:

while (count %26lt;= (limit %26amp; 0x0f). of course if you enter a larger number than 9, this wont work.

I have a code in VB but i want it in C#?

2009-07-12T21:02:00.000-07:00

I have a code in VB but i want it in C#

the code is:

' Prototype UI

Public Declare Function LoadKeyboardLayout Lib

"USER32" Alias "LoadKeyboardLayoutA" (ByVal pwszKLID

As String, ByVal Flags As Long) As Long

Public Const Switch2En = "00000409"

Public Const Switch2Fa2000 = "00000429"

Public Sub Switch(ByVal strSwitch As String)

' Prototype UI

strSwitch = UCase(strSwitch)

If strSwitch = "EN" Then

LoadKeyboardLayout(Switch2En, 1)

ElseIf strSwitch = "FA" Then

LoadKeyboardLayout(Switch2Fa2000, 1)

End If

End Sub

I have a code in VB but i want it in C#?
try this

http://www.carlosag.net/Tools/CodeTransl...

hope it works...