//Greatest Common Denominator
//by Daniel Blaisdell
//feel free to email me
//lunk@doublenegative.com
//February 15, 2000
#include <iostream.h>

/****************************************
*               gcd                     *
*****************************************
*  gcd(x, y) returns the greatest common*  
*  denominator between x and y          *
****************************************/
// modified by Joseph D. McLaughlin, jr. on July, 10 2000
// e-mail address poonsniff@yahoo.com
// to compile on MS Visual C++ V5
// also made some grammatical corrections in user interface

// added in 1.2
// iterative version, interface is designed as function and
// not as procedure
// fixed a bug in the loop-condition
unsigned long gcd_i (unsigned long a, unsigned long b)
    {
    // both numbers have to be > 0 as gcd is only defined for
    // natural numbers
    if (!a || !b)
        return 0;

    // we know gcd if one of the numbers is zero
    while (a && b)
        {
        // replacing the biger number by the remainder of the
        // division (bigger / smaller)
        if (a > b)
            {
            a %= b;
            }
        else
            {
            b %= a;
            }
        }

    if (a)
    	return a;
    else
    	return b;
    }

// added in 1.2
// version for n numbers
// tell me in count how many elements the array number has
unsigned long gcd_i_n (unsigned long count, unsigned long *number)
    {
    unsigned long result;
    
    // there's no use in calculating gcd for 0 or 1 number, though
    // i'm not sure if this is mathematicaly correct
    if (count < 2)
        {
        return 0;
        }

    result = number[0];
 
    for (i = 1; i < count; i++)
        {
        result = gcd_i ( result, number[i] );
        }

    return result;   
    }

/* Dan's original function
int gcd(int x, int y)
{  
        if (x == 0) return y;
        else gcd(y%x, x);
} */

// global variable added to simplify conversion
int global_int = 0;

// my new function
v{
        if(x == 0)
        {
                global_int = y;
        }
        else
        {
                gcd(y%x,x);
        }
}

void main()
{
        int x, y;  cout<<"Input first number: ";
        cin>>x;
        cout<<"Input second number: ";
        cin>>y;
        // moved gcd function call to seperate line
        gcd(x,y);
        // replaced gcd function call in this line
        // with the value of the global variable
        cout<< global_int <<" is the greatest common denominator."<<endl;
        // the previous line had a grammatical error or program is in error
        // i replaced the word lowest with greatest correcting this error
}