import java.awt.*;
import java.applet.*;
import java.util.Random;

/**
 * This class draws random points in and around a circle.
 */
public class Monte7 extends Applet
{
	private static Random randy;
	private int SIZE;
	private Image offScreenImage;
	private Graphics offScreenGraphics;

	public int numInside, numOutside;
	
	private int randomInRange(int low, int high)
	{
		return (Math.abs(randy.nextInt()) % (high-low+1)) + low;
	}
	
	private double distance(int x1, int y1, int x2, int y2)
	{
		return Math.sqrt(Math.pow(x1-x2, 2) + Math.pow(y1-y2, 2));	
	}
	
	public void init()
	{
		randy = new Random();
		Dimension dim = getSize();
		SIZE = Math.min(dim.width, dim.height);
		
		drawCircle();
	}
	
	public void drawCircle()
	{
		numInside = 0;  numOutside = 0;
		
		offScreenImage = createImage(SIZE, SIZE);
	    offScreenGraphics = offScreenImage.getGraphics();
		Graphics g = getGraphics();
		
		offScreenGraphics.clearRect(0,0,SIZE,SIZE);
		g.clearRect(0,0,SIZE,SIZE);
		
	    offScreenGraphics.setColor(Color.red);
        g.setColor(Color.red);
	    offScreenGraphics.fillOval(0, 0, SIZE, SIZE);
        g.fillOval(0, 0, SIZE, SIZE);
	}
	
	public void drawDots(int numPoints)
    {
		Graphics g = getGraphics();
		for (int i = 0; i < numPoints; i++) {
            int x = randomInRange(0, SIZE);
            int y = randomInRange(0, SIZE);
            if (distance(x, y, SIZE/2, SIZE/2) < SIZE/2) {
                offScreenGraphics.setColor(Color.white);
                g.setColor(Color.white);
                numInside++;
            }
            else {
                offScreenGraphics.setColor(Color.black);
                g.setColor(Color.black);
                numOutside++;
            }
            offScreenGraphics.drawLine(x, y, x, y);
            g.drawLine(x, y, x, y);
		}
    }
	
	public void paint(Graphics g)
	{
		g.drawImage(offScreenImage, 0, 0, null);
	}
}