/*
 * file: Point.java
 *
 * This extends the Point.java example in the clone directory.
 *	We now want our points to be comparable as well.
 *
 * @author Chee Yap
 *     Honors Basic Algorithms, Fall 2000
 */

class Point 
	implements Cloneable, Comparable // if missing, get runtime error
{
 public int x, y;

 Point() {
	x = 0; y = 0;
 }//Point()

 Point(int a, int b){
	x = a; y = b;
 }//Point(a,b)

 public int compareTo(Object oo){ 	// return -1 is this is less than o.

	Point o = (Point) oo;		// casting is necessary
	if ((o.x < this.x) || (o.x == this.x && o.y < this.y))
         	return 1;
        if ((o.x > this.x) || (o.x == this.x && o.y > this.y))
         	return -1;
        return 0;
    }

 public static void main (String[] args) 
	throws Exception
 {
                Point p = new Point(0,0);
                Point q = p;  // only reference is copied!
                p.x = 1;
		System.out.println(
		   "References p and q point to the same Point. Is p == q? ");
                if (p == q) System.out.println("   Yes, RIGHT!");
                else System.out.println("   No, ERROR!");

		System.out.println(
		   "References r is a clone of p. Is p == r? ");
                Point r = (Point)p.clone();    
                if (p == r) System.out.println("   Yes, ERROR!");
                else System.out.println("   No, RIGHT!");

		System.out.println("Comparing (1,0) to (1,0) returns "
			+ p.compareTo(q) );

		p = new Point(1,1);
		System.out.println("Comparing (1,1) to (1,0) returns "
			+ p.compareTo(q) );

		System.out.println("Comparing (1,0) to (1,1) returns "
			+ q.compareTo(p) );

                
 } //main method
} //Point Class