Assignment #1: Simple Classes

Implement a very minimal BigRational class. A BigRational stores a numerator and a denominator. For the purposes of this assignment, you may assume that there are no negative numbers, no zero denominators, etc. For this assignment you need to only implement the following methods:

A reasonable set of constructors suitable to implement the sample program below.
add
equals
toString

The internal data representation consists of two java.math.BigInteger objects representing the numerator and denominator, respectively. The rational number is always kept in reduced form.

Sample test program

class Assign1
{
    public static void main( String [ ] args )
    {
        BigRational r1 = new BigRational( "123456789023466" );         // Denominator is 1
        BigRational r2 = new BigRational( "1234567890234660", "10" );
        BigRational r3 = new BigRational( "3", "4" );
        BigRational r4 = new BigRational( "2", "3" );
        BigRational r5 = r3.add( r4 );                                 // 17/12
        BigRational r6 = new BigRational( "10", "120" );               // 1/12

        System.out.println( r1.equals( r2 ) );   // Should be true!
        System.out.println( r5.add( r6 ) );      // 3/2
        System.out.println( r5 );                // 17/12
    }
}

BigRational Sketch

Here is a sketch of BigRational.

import java.math.BigInteger;

public class BigRational
{
    /*
     * Constructor, assumes no funny stuff, so no error checks.
     * Reduces to lowest form by dividing numerator
     * and denominator  by their gcd.
     */
    public BigRational( String n, String d )
    {
        numerator = new BigInteger( n );
        denominator = new BigInteger( d ); 
        reduce( );
    }

    private void reduce( )
    {
        BigInteger gcd = numerator.gcd( denominator );
        numerator = numerator.divide( gcd );
        denominator = denominator.divide( gcd );
    }


    // Additional constructors at your discretion

    /*
     * Returns a new BigRational representing this+other
     * Make sure to reduce
     */
    public BigRational add( BigRational other )
    {
    }

    public String toString( )
    {
    }

    public boolean equals( Object other )
    {
    }

    private BigInteger numerator;
    private BigInteger denominator;
}