import java.util.*;


/** <b>RatNumComparator</b> implements a compare() between two RatNum Objects
 */
class RatNumComparator implements Comparator {

  // @requires r1 instanceof RatNum, r2 instanceof RatNum
  // TODO: Modify this compare method so that it returns
  // a negative number if r1 >  r2,
  // zero              if r1 == r2
  // a positive number if r1 <  r2
  // Integer.MAX_VALUE if r1.isNaN() && !r2.isNaN()
  // Integer.MIN_VALUE if r2.isNaN() && !r1.isNaN()
  // 0                 if r1.isNaN() && r2.isNaN()
  public int compare (Object r1, Object r2) {

    // Your code here.  Hint, if r1 = a/b and r2 = c/d,
    // then r1 < r2 iff a * d < b * c.
    return 0;
  }

}



/** This class contains a main method which fills a List with
 *  randomly generated RatNum objects and then sorts them using
 *  <b>RatNumComparator</b>
 */

public class RatNumSortingTest {

  // You should not need to modify this class
  // at all.  You only need to implement the compare method in the
  // class RatNumComparator.  The code below shows examples of how to
  // generate random numbers and use an Iterator.
  
  public static void main (String[] args) {

    // create a big list of RatNums, but not in a sorted order
    List ratnumList = new ArrayList();

    // Fill the list using randomly generated RatNum Objects:

    // 1.  First, create a random number generator
    Random generator = new Random();

    // 2. Populate the list by creating random numerators and denominators
    for (int i = 0; i < 10; i++) {
      int randomNumer = generator.nextInt (20);
      int randomDenom = generator.nextInt (5);
      ratnumList.add (new RatNum (randomNumer, randomDenom));
    }

    // 3. Now call the Collections.sort() using our custom comparator
    Collections.sort (ratnumList, new RatNumComparator());

    // 4. Print out the list to see verify correctness.
    System.out.println ("Contents of sorted list of RatNums:");
    System.out.println ("***********************************");
    for (Iterator i = ratnumList.iterator(); i.hasNext();) {
      RatNum nextInList = (RatNum) i.next();
      System.out.print (nextInList.unparse() + " ");
    }
    // extra line break to make the output look nice
    System.out.println ("");
  }

}