Computer Science / Programming Thread

[Det. Bart Lasiter]

EDIT: I'm going to be nothing for an hour and a half later today during school, and was wondering if anyone had an idea for a program that I could do. To know what I can do, I've completed everything up to strings on the cprogramming.com site.

You could try XML parsing or exploring the DirectX SDK, there'll never be a shortage of tutorials and/or sample code on either of those topics.

[BongoBob]

Well the computers at my school were down when I had the free time. Oh well, gotta clean the house up a little bit and then maybe I'll figure something out.

 

EDIT: I ended up just making my program loop, but I compiled it on Windows and uploaded it.

 

http://www.geocities.com/bongobob7686/circleprogram.zip (right click save as)

 

And as for the source...

#include <iostream>

using namespace std;

int mainmenu();			// Main menu of the program
int cmenu();			// Menu for the circumference choice
int amenu();			// Menu for the area choice
int cmchoice1();		// Finds the circumference given the diameter
int cmchoice2();		// Finds the circumference given the radius
int amchoice1();		// Finds the area given the radius
int amchoice2();		// Finds the area given the diameter
int mmenuinpt;			// Directs the user to the selected part of the program
int cmenuinpt;			// Directs the user to the selected part of the program
int amenuinpt;			// Directs the user to the selected part of the program
int exitmsg();			// Message displayed upon exit
float pi = 3.14;		// Tells the program that Pi equals 3.14
float r;			// Variable for radius
float d;			// Variable for diameter
int cform();			// Formula to find the circumference of a circle
int aform();			// Formula to find the area of a circle
int rfromd();			// Derives a radius from the diameter
int dfromr();			// Derives a diameter from the radius
float c;			// Variable for circumference
float a;			// Variable for the true area
int errormsg();			// Message displayed upon a user error
char stayleave;			// Variable for looping the program.


int main()
{
do {
mainmenu();
if ( mmenuinpt == 1 ) {
	cmenu();
	if ( cmenuinpt == 1 ) {
		cmchoice1();
	}
	else if ( cmenuinpt == 2 ) {
		cmchoice2();
	}
	else {
		errormsg();
	}
}
else if ( mmenuinpt == 2 ) {
	amenu();
	if ( amenuinpt == 1 ) {
		amchoice1();
	}
	else if ( amenuinpt == 2 ) {
		amchoice2();
	}
	else {
		errormsg();
	}
}
else if ( mmenuinpt == 3 ) {
	stayleave = 101;
}
else {
	errormsg();
}
} while ( stayleave != 101 && stayleave != 69 );
exitmsg();
}



int mainmenu()			// Main menu of the program
{
cout<<"1. Find the circumference of a circle\n";
cout<<"2. Find the area of a circle\n";
cout<<"3. Exit\n";
cout<<"Please enter your choice: ";
cin>> mmenuinpt;
cin.ignore();
}

int cmenu()			// Menu for the circumference choice
{
cout<<"\nWhich do you know about the circle, (1) the diameter, or (2) the radius: ";
cin>> cmenuinpt;
cin.ignore();
}

int cmchoice1()			// Finds the circumference given the radius
{
cout<<"\nPlease enter the diameter of the circle: ";
cin>> d;
cin.ignore();
cform();
cout<<"\nThe circumference of the circle is "<< c <<"\n";
cout<<"Enter m to return to the main menu, or enter e to exit: ";
cin>> stayleave;
cin.ignore();
}

int cmchoice2()			// Finds the circumference given the diameter
{
cout<<"\nPlease enter the radius of the circle: ";
cin>> r;
cin.ignore();
dfromr();
cform();
cout<<"\nThe circumference of the circle is "<< c <<"\n";
cout<<"Enter m to return to the main menu, or enter e to exit: ";
cin>> stayleave;
cin.ignore();
}

int amenu()			// Menu for the area choice
{
cout<<"\nWhich do you know about the circle, (1) the radius, or (2) the diameter: ";
cin>> amenuinpt;
cin.ignore();
}

int amchoice1()			// Finds the area given the diameter
{
cout<<"\nPlease enter the radius of the circle: ";
cin>> r;
cin.ignore();
aform();
cout<<"\nThe area of the circle is "<< a <<"\n";
cout<<"Enter m to return to the main menu, or enter e to exit: ";
cin>> stayleave;
cin.ignore();
}

int amchoice2()			// Finds the area given the radius
{
cout<<"\nPlease enter the diameter of the circle: ";
cin>> d;
cin.ignore();
rfromd();
aform();
cout<<"\nThe area of the circle is "<< a <<"\n";
cout<<"Enter m to return to the main menu, or enter e to exit: ";
cin>> stayleave;
cin.ignore();
}

int exitmsg()			// Message displayed upon exit
{
cout<<"\nThank you for using this program.\n";
cout<<"Press enter to exit.\n";
cin.get();
}

int rfromd()			// Derives a radius from the diameter
{
r = d / 2;
}

int dfromr()			// Derives a diameter from the radius
{
d = r * 2;
}

int cform()			// Formula to find the circumference of a circle
{
c = d * pi;
}

int aform()			// Formula to find the area of a circle
{
a = r * r;
a = a * pi;
}

int errormsg()
{
cout<<"\nError.\n";
char stayleave = 101;
}

 

Let me know what you think/if you have problems with it

[Sabretooth]

EDIT: I ended up just making my program loop, but I compiled it on Windows and uploaded it.

 

[n00b]Now that reminds me - does anybody know how to compile stuff in GWBASIC? I would love to make an .exe all by myself.[/n00b]

[TiE23]

Well the computers at my school were down when I had the free time. Oh well, gotta clean the house up a little bit and then maybe I'll figure something out.

 

EDIT: I ended up just making my program loop, but I compiled it on Windows and uploaded it.

 

http://www.geocities.com/bongobob7686/circleprogram.zip (right click save as)

 

Let me know what you think/if you have problems with it

Hell yah, that stuff looks like fun, I might want to check out that site you're using some time.

[Det. Bart Lasiter]

If anyone's interested, here's some source code examples for DirectX and physics programming. And I highly recommend the book they go with as well.

[BCanr2d2]

Biggest program - being part of a team doing a new Point Of Sale program for our stores. Whilst not writing the guts of it, we had to fix up the original programmers problems and then implement new stuff into it.

[BongoBob]

I took up one of the challenges on cprogramming.com, and made a little calculator program now in my first period. I havn't been able to compile it (why isn't there an online C++ compiler : | ), but I'm confident that it will compile and work pretty nicely.

 

#include <iostream>

using namespace std;

int add ( int x, int y )
{
result = x + y;
return result;
}

int subtract ( int x, int y )
{
result = x - y;
return result;
}

int multiply ( int x, int y )
{
result = x * y;
return result;
}

int divide ( int x, int y)
{
result = x * y;
return result;
}

void numinput()
{
cout<<"Enter the first number: ";
cin>> x;
cin.ignore();
cout<<"Now enter the second number: ";
cin>> y;
cin.ignore();
}

void exitmsg();
{
cout<<"Thank you for using this program.\n";
cout<<"Press enter to exit\n";
cin.get();
}

int main()
{
int x;
int y;
char choice;

do {
	cout<<"What would you like to do?\n";
	cout<<"[A]dd	       [s]ubtract\n"
	cout<<"[M]ultiply      [D]ivide\n";
	cout<<"          [E]xit\n";
	cin>> choice;
	cin.ignore();
	switch (choice) {
		case 65:
			numinput();
			cout<< x << " + " << y << " = " << add ( x, y );
			cout<<"\n";
			break;
		case 83:
			numinput();
			cout<< x << " - " << y << " = " << subtract ( x, y );
			cout<<"\n";
			break;
		case 77:
			numinput();
			cout<< x << " * " << y << " = " << multiply ( x, y );
			cout<<"\n";
			break;
		case 68:
			numinput();
			cout<< x << " / " << y << " = " << divide ( x, y );
			cout<<"\n";
			break;
		case 69:
			exitmsg();
			break;
		default:
			cout<<"Error, try again";
			break;
	}
} while ( choice != 69 );
}

 

If someone wants to compile this and see if it works, go right ahead

[ET Warrior]

Suggestions: I didn't try compiling the code, though I doubt it will work the way you're hoping it will.

 

numinput();
cout<< x << " + " << y << " = " << add ( x, y );
cout<<"\n";

 

Dollars to doughnuts x and y will be garbage values, and your math functions will return garbage values.

 

In fact, I'd be willing to bet you won't get it to compile, and the error lies in your numinput function. You should try to figure out what the problem is yourself, but I will tell you that it's a problem.

[BongoBob]

Thanks, I'll try compiling it after I eat

 

EDIT: I realized I messed up some stuff, so I fixed it and everything compiled smoothly

 

Here's the updated source code:

 

#include <iostream>

using namespace std;

int x;
int y;
float result;

int add ( int x, int y );
int subtract ( int x, int y );
int multiply ( int x, int y );
int divide ( int x, int y);
void numinput();
void exitmsg();
void resetinpt();

int main()
{
char choice;

do {
       cout<<"What would you like to do?\n";
	cout<<"[A]dd	       [s]ubtract\n";
	cout<<"[M]ultiply      [D]ivide\n";
	cout<<"          [E]xit\n";
	cin>> choice;
	cin.ignore(); 
       cout<<"\n";
	switch (choice) {
		case 65:
			numinput();
			cout<< x << " + " << y << " = " << add ( x, y );
			break;
		  case 83:
			numinput();
	    	cout<< x << " - " << y << " = " << subtract ( x, y ) << "\n";
			break;
		  case 77:
			numinput();
			cout<< x << " * " << y << " = " << multiply ( x, y );
			break;
		  case 68:
			numinput();
			cout<< x << " / " << y << " = " << divide ( x, y );
			cout<<"\n";
			break;
		case 69:
			exitmsg();
			break;
		default:
			cout<<"Error, try again";
			break;
	}
	resetinpt();
} while ( choice != 69 );
}

int add ( int x, int y )
{
return x + y;
}

int subtract ( int x, int y )
{
   return x - y;
}

int multiply ( int x, int y )
{
   return x * y;
}

int divide ( int x, int y )
{
   return x / y;
}

void numinput()
{
    cout<<"Please enter the first number: ";
    cin>> x;
    cin.ignore();
    cout<<"Please enter the second number: ";
    cin>> y;
    cin.ignore();
}

void resetinpt()
{
    x = 0;
    y = 0;
}

void exitmsg()
{
    cout<<"Thanks for using this program.\n";
    cout<<"Press enter to exit.\n";
    cin.get();
}

[MTV2]

man, the best i could do is just make a pong game in QBasic...and that took awhile >.<

[ET Warrior]

Global variables make me die a little inside.

 

Also, your math functions are entirely superfluous. why not just

cout<< x << " + " << y << " = " << x+y;

for the addition, etc.

 

Aaand furthermore, are you using the ascii numerical values for the character in your switch statement? I would suggest perhaps

 

switch(toupper(choice))
{
   case 'A':
   etc. etc.
}

[BongoBob]

Global variables make me die a little inside.

 

Also, your math functions are entirely superfluous. why not just

cout<< x << " + " << y << " = " << x+y;

for the addition, etc.

 

I was just messin around with functions. I know I could just do that, but I didn't wanna

 

Aaand furthermore, are you using the ascii numerical values for the character in your switch statement? I would suggest perhaps

 

switch(toupper(choice))
{
   case 'A':
   etc. etc.
}

 

What's toupper? I havn't learned about that yet

 

Btw, I'm goin to borders to get a C++ book today

[ET Warrior]

toupper is a nifty function that takes the input (not entirely sure if it only takes a char, or if it can take a char*, or if it can take strings aswell...I'd have to look it up)...anywho, takes that input and if it's already an upercase character it does nothing, but if it's lowercase it returns the same character only capitalized. If you want a user to be able to input 'a' or 'A' and get the same functionality, toupper is prettttty useful.

 

I recommend eliminating your global variables, it'd give you practice with pass-by-reference, and global variables are ugly.

[BongoBob]

Will do when I get home. Thanks

[Det. Bart Lasiter]

Note to all using VC++ 2005 Express Edition:

To build Win32 applications with this IDE, you'll need to follow these steps.