import javax.swing.*; 
import java.awt.event.*;
import java.awt.*; 

class Six extends JFrame {
  Seven component; 
  Six(String title, int width) {
    this.component = new Seven(); 
    this.add( this.component );
    this.setSize(width, width); 
    this.setTitle(title); 
    this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);  
    this.setVisible(true); 
  }
  public static void main(String[] args) {
    Six frame = new Six("Finding PI", 600); 
    frame.component.calculate(); 
  }
}

class Seven extends JComponent {
  int times, size, inside, total; 
  Point center; 
  public void paintComponent(Graphics g) {
    this.size = this.getHeight(); 
    this.center = new Point(size/2, size/2);
    this.total = this.inside = 0; 
    g.setColor(Color.BLUE); 
    g.drawOval(0, 0, this.size, this.size);
    if (this.times > 0) { 
      for (int i = 0; i < this.times; i = i + 1) {
        Point p = new Point(size); 
        if (p.distanceTo(this.center) < size/2) { 
          this.inside += 1; 
          g.setColor(Color.RED); 
        } else 
          g.setColor(Color.BLUE); 
        g.drawLine(p.x, p.y, p.x, p.y); 
        this.total += 1;       
      } 
      System.out.println( "In " + this.times + " simulation steps PI is estimated to " + 4.0 * this.inside / this.total ); 
    } 
  } 
  void calculate() {
    String input = JOptionPane.showInputDialog("How many times?"); 
    if (input == null || input.equals("bye")) 
      System.exit(0); 
    else {
      try{ 
        this.times = Integer.parseInt( input ); 
        this.repaint(); 
      } catch (Exception e) {
        System.out.println("Please enter a number or bye."); 
      } finally {
        this.calculate(); 
      }
    } 
  } 
}

class Point { 
  int x, y; 
  Point(int size) {
    this((int)(Math.random() * size), (int)(Math.random() * size)); 
  }
  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) ); 
  } 
}