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

public class Centroid  extends JApplet {
    
    int points;
    
    public void init() {
    	String input;
	
	input = JOptionPane.showInputDialog("Enter # of points");
	points = Integer.parseInt(input);
	
    }
    
   
     public void paint (Graphics g) {
        super.paint(g);  

 	int [][] P = new int [2][points]; 
	int sumX=0, sumY=0;
	double sumDist=0, sumDistMid=0, sumDistNear=0;
	double distUpLeft, distUpRight, distDownRight, distDownLeft;
	double minUpLeft=10000, minUpRight=10000, minDownLeft=10000,minDownRight=10000;
	int minUpLeftIndex=-1, minUpRightIndex=-1, minDownLeftIndex=-1, minDownRightIndex=-1;
	int xc, yc;

	for (int j=0; j<points; j++) {
	    P[0][j] = (int)(Math.random()*getWidth());
	    P[1][j] = (int)(Math.random()*getHeight());
	    sumX += P[0][j];
	    sumY += P[1][j];
	}
	xc = sumX/points;  //average X value
	yc = sumY/points;
	g.setColor(Color.RED);
	g.fillRect(xc,yc, 3,3);  //centroid
	
	for (int j=0; j<points; j++) { //lines to centroid
	    g.drawLine(xc,yc, P[0][j],P[1][j]); 
	    sumDist += Math.sqrt((xc-P[0][j])*(xc-P[0][j]) + 
	    	                 (yc-P[1][j])*(yc-P[1][j]));
	    sumDistMid += Math.sqrt((getWidth()/2-P[0][j])*(getWidth()/2-P[0][j]) + 
	    	                    (getHeight()/2-P[1][j])*(getHeight()/2-P[1][j]));
	    sumDistNear += Math.sqrt((xc-P[0][j])*(xc-P[0][j]) + 
	    	                     (yc-10-P[1][j])*(yc-10-P[1][j]));
	}
	g.drawString("sumDist="+sumDist, 1, 20);    
	g.drawString("sumDistMid="+sumDistMid, 1, 40);    
	g.drawString("sumDistNear="+sumDistNear, 1, 60);    
	g.setColor(Color.GREEN);
	g.fillRect(getWidth()/2,getHeight()/2, 3,3);
		
	    		
//	while (true) {
	g.setColor(Color.RED);
	for (int j=0; j<points; j++) //lines to centroid
	    g.drawLine(xc,yc, P[0][j],P[1][j]); 
	g.setColor(Color.BLACK);
	for (int j=0; j<points; j++)  //the points
	    g.fillRect(P[0][j],P[1][j],  3,3);
	    
	for (int j=0; j<points; j++) {
	    distUpLeft = Math.sqrt((0-P[0][j])*(0-P[0][j]) + 
	    	                 (0-P[1][j])*(0-P[1][j]));
	    if (distUpLeft < minUpLeft) {
	    	minUpLeft = distUpLeft;
	    	minUpLeftIndex = j;
	    }
	   
	    distUpRight = Math.sqrt((getWidth()-P[0][j])*(getWidth()-P[0][j]) + 
	    	                 (0-P[1][j])*(0-P[1][j]));
	    if (distUpRight < minUpRight) {
	    	minUpRight = distUpRight;
	    	minUpRightIndex = j;
	    }	    
	    	
	    distDownLeft = Math.sqrt((0-P[0][j])*(0-P[0][j]) + 
	    	                 (getHeight()-P[1][j])*(getHeight()-P[1][j]));
	    if (distDownLeft < minDownLeft) {
	    	minDownLeft = distDownLeft;
	    	minDownLeftIndex = j;
	    }	    
	    	
	    distDownRight = Math.sqrt((getWidth()-P[0][j])*(getWidth()-P[0][j]) + 
	    	                 (getHeight()-P[1][j])*(getHeight()-P[1][j]));
	    if (distDownRight < minDownRight) {
	    	minDownRight = distDownRight;
	    	minDownRightIndex = j;
	    }	
	}	

	g.setColor(Color.MAGENTA);
	
	g.drawLine(P[0][minUpLeftIndex],P[1][minUpLeftIndex],
	           P[0][minUpRightIndex],P[1][minUpRightIndex]);
	g.drawLine(P[0][minDownRightIndex],P[1][minDownRightIndex],
	           P[0][minUpRightIndex],P[1][minUpRightIndex]);
	g.drawLine(P[0][minDownRightIndex],P[1][minDownRightIndex],
	           P[0][minDownLeftIndex],P[1][minDownLeftIndex]);
	g.drawLine(P[0][minUpLeftIndex],P[1][minUpLeftIndex],
	           P[0][minDownLeftIndex],P[1][minDownLeftIndex]);
	    
/*	try {
	    Thread.sleep(1000);
	}
	catch (InterruptedException e) {
	}
        super.paint(g);  //clear screen?
	g.setColor(Color.RED);
 	for (int j=0; j<points; j++) 
	    g.drawLine(xc,yc,(P[0][j]+xc)/2,(P[1][j]+yc)/2);       
	g.setColor(Color.BLACK);
 	for (int j=0; j<points; j++) 
 	    g.fillRect((P[0][j]+xc)/2,(P[1][j]+yc)/2, 3,3);
 	    
	try {
	    Thread.sleep(1000);
	}
	catch (InterruptedException e) {
	}
*/       // super.paint(g);  //clear screen?
         	    
//	}  //while
		
     }
}