/* <applet code=One.class width=300 height=300>
   </applet>
 */

import java.applet.*; 
import java.awt.*; 
import java.awt.event.*; 

public class One extends Applet implements MouseMotionListener {

  Circle[] circles = new Circle[100];

  public void init() {
    this.addMouseMotionListener(this);  
    
    for (int i = 0; i < this.circles.length;  i++) {
      Point center = new Point((int)(Math.random() * 600 + 50), 
                               (int)(Math.random() * 600 + 50) ); 
      int radius = (int)(Math.random() * 80 + 10) ; 

      Color color = new Color( (float) Math.random(), 
                               (float) Math.random(), 
                               (float) Math.random()); 

      this.circles[i] = new Circle(center, radius, color);
    } 
  }   

  public void paint(Graphics g) {
    for (int i = 0; i < this.circles.length; i++) 
      this.circles[i].draw(g); 
    
  } 

  public void mouseDragged(MouseEvent e) { 
    if (this.currentCircle != null) 
      this.currentCircle.move(e.getX(), e.getY()); 
    else 
      for (int i = 0; i < this.circles.length; i++)
        if (this.circles[i].contains(e.getX(), e.getY())) {
          this.currentCircle = this.circles[i];
          break; 
        } 
    this.repaint(); 
  }   

  Circle currentCircle; 

  public void mouseMoved(MouseEvent e) { 
    this.currentCircle = null;     
  }   
}

class Circle {
  Point center;
  int radius; 

  Color color; 

  void move(int x, int y) {
    this.center = new Point(x+radius/2, y+radius/2); 
  } 

  boolean contains(int x, int y) {
    Point a = new Point(x, y); 
    return a.distanceTo(this.center) < this.radius; 
  } 

  Circle(Point c, int r, Color color) {
    this.center = c; 
    this.radius = r; 
    this.color = color; 
  } 
  void draw(Graphics g) {
    g.setColor(this.color); 
    g.fillOval(center.x - radius, center.y - radius, radius, radius); 
    g.setColor(Color.BLACK); 
    g.drawOval(center.x - radius, center.y - radius, radius, radius);     
  }
} 

class Point {
  int x, y; 
  Point(int x, int y) {
    this.x = x;
    this.y = y;
  }
  double distanceTo(Point other) {
    return Math.sqrt(Math.pow(this.x - other.x, 2) + 
                     Math.pow(this.y - other.y, 2)); 
  }
}