// CS212 CS 2 Assignment 3
// Due: Monday February 28, 2011
//
// File Name: cs2assign3.cpp
// Author: Jennifer Whiley
// Instuctor: Dr. Wang
//
// Compile: g++ cs2assign3.cpp
// Run: ./a.out < in2.txt > out3.txt
// Goal: The program will read fractions (using class)
//       and output each student's average to a file called out3.txt;
//       the program will perform the operations indicated.
//   	 ("+", "-", "*", "/")

#include <iostream>
using namespace std;

class Fraction
{
        int numr;
        int deno;
/*
	void reduce()
	{
		int n = numr;
		int d = deno;
		while(d != 0)
		{
			int f = n % d;
			n = d;
			d = f;
		}
		if (d != 0)
		{
			numr /= n;
			deno /= n;
		}
		if (deno < 0)
		{
			numr *= (-1);
			deno *= (-1);
		}
	}
*/
        void reduce()
        {
                int n = numr;
                int d = deno;

                //find GCD: n
                while( d != 0 )
                {               int r = n % d;
                        n = d;
                        d = r;
                }

                // process
                if ( n != 0 )
                {       numr /= n;
                        deno /= n;
                }
                if (deno < 0)
                {
                        numr *= (-1);
                        deno *= (-1);
                }
        }

public:
	Fraction()
	{
                numr = 0;
                deno = 1;
	}
	Fraction(int n, int d)
        {
                numr = n;
                deno = d;
        }
        void Set(int n, int d)
        {       numr = n;
                deno = d;
//		reduce();
        }
        void Print() const 
        {
                cout << numr << "/" << deno;
        }
        Fraction Addition (Fraction x)
        {
                Fraction ans;
                ans.numr = numr * x.deno + deno * x.numr;
                ans.deno = deno * x.deno;
                // use the reduce()
                // ????
                ans.reduce();
                return ans;
        }
        Fraction Subtraction (Fraction x)
        {
                Fraction ans;
                ans.numr = numr * x.deno - deno * x.numr;
                ans.deno = deno * x.deno;
                ans.reduce();
                return ans; 
	}	
	Fraction Multiplication (Fraction x)
	{
		Fraction mult;
		mult.numr = numr * x.numr;
		mult.deno = deno * x.deno;
		mult.reduce();
		return mult;
	}
	Fraction Division (Fraction x)
	{
		Fraction div;
		div.numr = numr * x.deno;
		div.deno = deno * x.numr;
		div.reduce();
		return div;
	}
};

int main()
{	
        Fraction a, b, c;       // c = a + b
        Fraction d, e, f;       // d = a - b; e = a * b
        int an, ad, bn, bd;
        cout << "The 1st fraction (nume, deno); ";
        cin >> an >> ad;
        cout << "The 2nd fraction (nume, deno); ";
        cin >> bn >> bd;
        a.Set(an, ad);
        b.Set(bn, bd);

        c = a.Addition(b);
        e = a.Multiplication(b);
        a.Print();      // 1/2
        cout << " + ";
        b.Print();      // 3/4
        cout << " = ";
        c.Print();
        cout << "\n\n";
        a.Print();      // 1/2
        cout << " * ";
        b.Print();      // 3/4
        cout << " = ";
        e.Print();

        cout << "\n\nHi.\n\n.";
	
	return 0;
}