//	File name:	assign4.cpp
//	Author:		Christie Abbott
//	Instructor:	Dr. Wang	
//	Due Date:	February 27, 2008
//	Compiling:	g++ assign4.cpp
//	Execution:	./a.out
//	Goal: The program will perform the following operations on two fractions,
//		(+, -, /, *).

#include <iostream>

using namespace std;

class Fraction
{
	int numerator, denominator;
public:
	Fraction()
	{	numerator = 0;
		denominator = 1;
	}
	Fraction(int n, int d)
	{	numerator = n;
		denominator = d;
	}
	void Set(int n, int d)
	{	numerator = n;
		denominator = d;
	}
	void Write() const
	{	
		cout << numerator << '/' << denominator;	
	}
	void Reduce()
	{
                int n = numerator;
                int d = denominator;
                while( d != 0 )
                {
                        int r = n % d;
                        n = d;
                        d = r;
                }
                if ( n != 0 )
                {
                        numerator /= n;
                        denominator /= n;
        	}
		if (denominator < 0)
                {
                        numerator *= (-1);
                        denominator *= (-1);
                }
                return;
        }
	Fraction operator* (Fraction f)
	{ 	Fraction t;
		int n, d;
		n = numerator * f.numerator;
		d = denominator * f.denominator;
		t.Set(n, d);
		t.Reduce();
		return t;	
	}
	  Fraction operator+ (Fraction g)
        {       Fraction t;
                int n, d;
                n = numerator * g.denominator + denominator * g.numerator;
                d = denominator * g.denominator;
                t.Set(n, d);
		t.Reduce();
                return t;
        }
	  Fraction operator- (Fraction s)
        {       Fraction t;
                int n, d;
                n = (numerator * s.denominator) - ( denominator *s.numerator);
                d = denominator * s.denominator;
                t.Set(n, d);
		t.Reduce();
                return t;
        }
	  Fraction operator/ (Fraction a)
        {       Fraction t;
                int n, d;
                n = numerator * a.numerator;
                d = denominator * a.denominator;
                t.Set(n, d);
		t.Reduce();
                return t;
        }

};

int main()
{
	Fraction x;
	Fraction y;
	Fraction z;
	int n, d;
	char dummy;
	char op;
	
	cout << "Input x (n/d), -1/1 to quit): ";
	cin >> n >> dummy >> d;
	while (n != -1 &&  d != 1)
	{
		x.Set(n, d);
		cout << "Input y (n/d): ";
        	cin >> n >> dummy >> d;
        	y.Set(n, d);
		cout << "Operation? (+, -, *, /) ";
		cin >> op;
		if( op == '*')
			z = x * y;
		else if( op == '+')
			z = x + y;
		else if( op == '-')
			z = x - y;
		else if( op == '/')
			z = x / y; 
				
		cout << "\n";
		x.Write();
		cout << " " << op << " ";
		y. Write();
		cout << " = ";
		z.Write();
		cout << "\n";
	
		cout << "\n\nInput x (n/d), -1/1 to quit): ";
        	cin >> n >> dummy >> d;
	}
	
	cout << "\n\nBye.\n\n";
	return 0;
}