yhsj.java

杨辉三角 用java实现

import java.awt.*;
import java.applet.*;
import java.awt.event.*;
public class Yhsj extends Applet implements ActionListener
{
	TextField input=new TextField(5);
	Button ok=new Button("绘制杨辉三角形");
	
	public void init()
	{
		add(input);
		add(ok);
		
		ok.addActionListener(this);
		
		
	}	
	
	public void paint(Graphics g)
	{
		int l=Integer.parseInt(input.getText());
		
		for(int y=0;y<l;y++)
		{
			for(int x=0;x<=y;x++)
			{
				g.drawString(String.valueOf(c(y,x)),(int)(250+(x-y/(float)2)*40),50+20*y);
			
			}
		
			
		}
	
	}
	public void actionPerformed(ActionEvent e)
	{
		repaint();
	
	}
	private static int c(int b,int t)
	{
		if(t==0|t==b)
			return 1;
		
		return p(b)/p(t)/p(b-t);
		
	}
	
	private static int p(int i)
	{
		
		if(i==0|i==1)
			return 1;
		
		int result=1;
		
		for(int m=1;m<=i;m++)
		{
			result*=m;
		
		}
		
		return result;
	}


}