/*
   There's something funny about this program (not that there are any
   errors), which concerns the nature of OOP in C++/Java/C#.  In
   particular, pay attention to the usage of "public" and "private".
   Don't take everything about these languages for granted!  Think
   about possible alternatives.  
*/

#include<iostream.h>

#define BOOLEAN int

class fraction
{
    private:
      int numerator;
      int denominator;
      int gcd(int a, int b) 
      { if (a==0) return b; else return gcd(b%a,a); } // euclid's alg

    public:

    fraction(int n, int d)  // constructor
    {
       if (d==0) d = 1;
       int cd = gcd(n,d);  // common divisor  
       numerator = n/cd;
       denominator = d/cd;
    }

    ~fraction() {}  // trivial destructor
   
    // check if one fraction is equal to another fraction:
    BOOLEAN equals(fraction *f)
    {
       return numerator*f->denominator == denominator*f->numerator;
    }

    // multiply fractions
    fraction* mult(fraction *f)
    {
       return 
        new fraction(numerator*f->numerator,denominator*f->denominator);
    }
};   // end of class fraction

int main(int argc, char **argv)
{
  fraction *f1, *f2, *f3;
  f1 = new fraction(1,3);
  f2 = new fraction(2,5);
  f3 = f1->mult(f2);
  if (f3->equals(new fraction(2,15))) cout << "nice program!\n";
  return 0;
}