/*
	A matrix demo for the Pascal Triangle
	Dan Warner  9/7/2000
*/

import java.awt.*;
import java.applet.Applet;

public class PascalTriangle extends Applet
{
	int[][] pascalTri = new int[12][];

	public void init() {

        //populate matrix
        for (int i = 0; i < pascalTri.length; i++) {
            pascalTri[i] = new int[i+1];    //create sub-array
            pascalTri[i][0] = 1;
            for (int j = 1; j < (pascalTri[i].length - 1); j++) {
	            pascalTri[i][j] = pascalTri[i-1][j-1] + pascalTri[i-1][j];
            }
            pascalTri[i][i] = 1;
        }
		repaint();
	}
	
	public void paint( Graphics g ) {
		String line;
		// Color the background
		g.setColor(Color.cyan);
		g.fillRect(0, 0, 430, 250);
		// Draw the title
		g.setColor(Color.red);
		Font myFont = new Font("Helvetica", Font.BOLD, 24);
		g.setFont(myFont);
		g.drawString( "Pascal's Triangle", 40, 25 );
		// Display the matrix
		myFont = new Font("Courier", Font.PLAIN, 14);
		g.setFont(myFont);
        for (int i = 0; i < pascalTri.length; i++) {
        	line = " ";
            for (int j = 0; j < pascalTri[i].length; j++) {
            	if (pascalTri[i][j] < 10) {
            		line += "   " + pascalTri[i][j];
            	} else if (pascalTri[i][j] < 100) {
            		line += "  " + pascalTri[i][j];
            	} else {
            		line += " " + pascalTri[i][j];
            	}
            }
			g.drawString( line, 10, 50+i*15 );
        }
    }
}