CSCI A201/A597 and I210 Problem Set Four Second semester 2000-2001

Your fourth assignment consists of only one problem, due on

Saturday, March 3, 2001 at the end of the day

Strict due date is

Sat Mar 3 at 11:59pm

It provides tests for each of the ten features of your class definition.

Implement a class Fraction that works as follows:

Assume the following test program:

public static void main(String[] args) {
  Fraction f = new Fraction(6, 9);
  Fraction g = new Fraction(-4, 6); 
  System.out.println("Test of operations: "); 
  System.out.println("  Add: " + f + " + " + g + " = " + f.plus(g)); 
  System.out.println("  Sub: " + f + " - " + g + " = " + f.minus(g)); 
  System.out.println("  Mul: " + f + " * " + g + " = " + f.times(g)); 
  System.out.println("  Div: " + f + " / " + g + " = " + f.divideBy(g)); 
  System.out.println("Test of predicates: "); 
  System.out.print("  1. Does " + f + " equal " + g + "? "); 
  System.out.println(" The answer is: " + f.equals(g)); 
  Fraction h = new Fraction(8, -2); 
  System.out.print("  2. Is " + h + " an integer? "); 
  System.out.println("The answer is: " + h.isInt()); 
  Fraction i, j; 
  i = (f.minus(g)).times(f.plus(g));
  j = f.times(f).minus(g.times(g));
  System.out.print("  3. Does " + i + " equal " + j + "? "); 
  System.out.println("The answer is: " + i.equals(j)); 
  System.out.print("  4. Is 5/8 greater than 2/3? The answer is: "); 
  System.out.println((new Fraction(5, 8)).greaterThan(new Fraction (2, 3))); 
}

Test of operations: 
  Add: 2/3 + (-2/3) = 0
  Sub: 2/3 - (-2/3) = 4/3
  Mul: 2/3 * (-2/3) = (-4/9)
  Div: 2/3 / (-2/3) = (-1)
Test of predicates: 
  1. Does 2/3 equal (-2/3)?  The answer is: false
  2. Is (-4) an integer? The answer is: true
  3. Does 0 equal 0? The answer is: true
  4. Is 5/8 greater than 2/3? The answer is: false

class Euclid {
  static int gcd(int a, int b) { 
    a = Math.abs(a); 
    b = Math.abs(b); 
    if (a == 0) return b; // 0 is error value 
    if (b == 0) return a; 
    int temp;
    while (b > 0) {
      temp = a % b; 
      a = b; 
      b = temp; 
    }
    return a; 
  }
}