CSCI A201/A597 Solutions Assignment Ten: Packing Bins

import element.*;

public class hw10 {
    public static void main(String[] args) {
	Circle[] circles = new Circle[100]; 
	DrawingWindow d = new DrawingWindow(); 
	d.invertMode(); 
	Rect bin= new Rect(10, 10, 130, 180); 
	d.draw(bin); 
	int radius = (int)(Math.random() * 20 + 10); 
	Pt start = new Pt(175, 175); 
	Circle c = new Circle(start, radius); 
	d.draw(c); 
	boolean gameOn = true; 
	int number = 0; 
	int score = 0; 
	Library.showScore(d, score); 
	while (gameOn) {
	    d.awaitMousePress(); 
	    while (d.mousePressed()) {
		Pt m = d.getMouse(); 
		d.draw(c); 
		c.center(m); 
		d.draw(c); 
	    } 
	    boolean placementOK = true; 
	    Rect vb = new Rect(bin.left() + c.radius(), 
			       bin.top() + c.radius(), 
			       bin.width() - 2 * c.radius(), 
			       bin.height() - 2 * c.radius()); 
	    if (!vb.contains(c.center())) {
		placementOK = false; 
		gameOn = false; 
	    } 
	    for (int i = 0; i < number; i++) {
		if (Library.overlap(c, circles[i])) {
		    placementOK = false; 
		}
	    }
	    if (placementOK) {
		score += Math.PI * c.radius() * c.radius(); 
		Library.showScore(d, score); 
		circles[number] = c; 
		number += 1; 
		d.fill(c); 
		radius = (int)(Math.random() * 20 + 10); 
		c = new Circle(start, radius); 
		d.draw(c); 
	    } else {
		d.draw(c); 
		c.center(start); 
		d.draw(c); 
	    } 
	}
	System.out.println("Thanks for playing, your final score was: " +
                            score); 
	Pt m = d.awaitMouseClick(); 
	System.exit(0); 
    }
} 

class Library {
    public static void showScore(DrawingWindow d, int score) {
	Rect scoreBox = new Rect(150, 30, 40, 20); 
	d.paintMode(); 
	d.clear(scoreBox);
	d.draw(scoreBox); 
	Text t = new Text(score);
	t.center(scoreBox.center()); 
	d.draw(t); 
	d.invertMode(); 
    } 
    public static boolean overlap(Circle a, Circle b) {
	return Library.distance(a.center(), b.center()) <
	    a.radius() + b.radius(); 
    } 
    public static double distance(Pt a, Pt b) {
	int h = a.x() - b.x(), 
	    v = a.y() - b.y(); 
	return Math.sqrt(h * h + v * v); 
    }
}