erfensousuo.java

来自「二分搜索算法程序源码,动态演示过程.JAVA源码.」· Java 代码 · 共 271 行

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

public class erfensousuo
{
	/**
     * Creates a new instance of <code>Newton</code>.
     */
    public erfensousuo() {
    }
    
    /**
     * @param args the command line arguments
     */
   public static void main(String[] arg)
   {
      new newFrame().init();
   }
}

class newFrame extends JFrame
{
    public void init()  
    {
    	MyPanel hello=new MyPanel();
        getContentPane().add(hello);
        hello.thread.start();

        //以下代码设置JFrame窗体的外观
        setSize(400,400);
        setLocation(200,200);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setVisible(true);
    }
}

class MyPanel extends JPanel implements Runnable
{
    Thread thread;
    
    private int xpoints[];                
    private double ypoints[];
    
    private double a,b;               
	private double a1 = 50.0;
	private double b1 = 100.0;
	private double b2=50.0;
	private double a2=-50.0;
	private double b3=-50;
	private double a3=-100;
	private double e = 0.001;
	
	private double A1=Math.PI/2;
	private double B1=Math.PI;
	private double B2=Math.PI/2;
	private double A2=-Math.PI/2;
	private double B3=-Math.PI/2;
	private double A3=-Math.PI;
		
	private double x,xx,z1,z2,z3,fa,fx;
	int hh1=0,hh2=0,hh3=0;

    public MyPanel() 
    {
        setSize(500, 500);                   

        xpoints=new int[401];                
        ypoints=new double[401];             

        thread=new Thread(this); 
    }

    public void run()  
    {
    	 a=a1;b=b1;
    	 repaint();
    	 
    	 try{
    	 	thread.sleep(1000);
    	 }catch(InterruptedException e)
    	 {
    	 }
    	 
    	 while(B1-A1>e)                  //求第一个值
    	 {
    	 	x=(A1+B1)/2;
    	 	xx=(a1+b1)/2;
    	 	fx=2*Math.sin(x)-x;
    	 	fa=2*Math.sin(A1)-A1;
    	 	if(fx*fa<0)
    	 	{
    	 		B1=x;
    	 		b=b1=xx;
    	 		repaint();
    	 		try{
    	 			thread.sleep(1000);
    	 		}catch(InterruptedException e)
    	        {
    	        }
    	 		
    	 	}
    	 	else
    	 	{
    	 		A1=x;
    	 		a=a1=xx;
    	 		repaint();
    	 		try{
    	 	        thread.sleep(1000);
    	        }catch(InterruptedException e)
    	        {
    	        }	
    	 	}
    	 }
    	 hh1=1;
    	 z1=(A1+B1)/2;
    	 repaint();
    	 try{
    	 	thread.sleep(1000);
    	 }
    	 catch(InterruptedException e)
    	 {
    	 }
    
    	 a=a2;b=b2;
    	 repaint();
    	 
    	 try{
    	 	thread.sleep(1000);
    	 }catch(InterruptedException e)
    	 {
    	 }
    	 
    	 while(B2-A2>e)       //求第二个值
    	 {
    	 	x=(A2+B2)/2;
    	 	xx=(a2+b2)/2;
    	 	fx=2*Math.sin(x)-x;
    	 	fa=2*Math.sin(A2)-A2;
    	 	if(fx*fa<=0)
    	 	{
    	 		B2=x;
    	 		b=b2=xx;
    	 		repaint();
    	 		try{
    	 			thread.sleep(1000);
    	 		}catch(InterruptedException e)
    	        {
    	        }
    	 		
    	 	}
    	 	else
    	 	{
    	 		A2=x;
    	 		a=a2=xx;
    	 		repaint();
    	 		try{
    	 	        thread.sleep(1000);
    	        }catch(InterruptedException e)
    	        {
    	        }	
    	 	}
    	 }
    	 hh2=1;
    	 z2=(A2+B2)/2;
    	 repaint();
    	 try{
    	 	thread.sleep(1000);
    	 }
    	 catch(InterruptedException e)
    	 {
    	 }
    	 a=a3;b=b3;
    	 repaint();
    	  try{
    	 	thread.sleep(1000);
    	 }
    	 catch(InterruptedException e)
    	 {
    	 }
    	 
    	  while(B3-A3>e)                  //求第三个值
    	 {
    	 	x=(A3+B3)/2;
    	 	xx=(a3+b3)/2;
    	 	fx=2*Math.sin(x)-x;
    	 	fa=2*Math.sin(A3)-A3;
    	 	if(fx*fa<0)
    	 	{
    	 		B3=x;
    	 		b=b3=xx;
    	 		repaint();
    	 		try{
    	 			thread.sleep(1000);
    	 		}catch(InterruptedException e)
    	        {
    	        }
    	 		
    	 	}
    	 	else
    	 	{
    	 		A3=x;
    	 		a=a3=xx;
    	 		repaint();
    	 		try{
    	 	        thread.sleep(1000);
    	        }catch(InterruptedException e)
    	        {
    	        }	
    	 	}
    	 }
    	 hh3=1;
    	 z3=(A3+B3)/2;
    	 repaint();
     }

     public void paintComponent(Graphics g)   
     {
     	for(int i=0,x=-200;i<=400;i++)
     	{
     		xpoints[i]=x;
     		ypoints[i]=150*Math.sin(Math.PI*xpoints[i]/100);
     		x++;
     	}
     
    
         g.setColor(Color.white);              
         g.clearRect(0, 0, 400, 440);   

         //画坐标轴
         g.setColor(Color.red);     
         g.drawLine(0, 200, 400, 200);   //x轴
         g.drawLine(200, 400, 200, 0);  //y轴
         
         g.translate(200,200);
         
        
        
         g.setColor(Color.green);
         
         g.drawLine(200,-473,-200,473);
         
         for(int i=0;i<400;i++)
         {
         	g.drawLine(xpoints[i],-(int)ypoints[i],xpoints[i+1],-(int)ypoints[i+1]);
         }
         
         g.setColor(Color.black);
         
         g.drawLine((int)a,-200,(int)a,200);
         
         g.drawLine((int)b,-200,(int)b,200);
         
         if(hh1==1)
         {
         	g.drawString("x1="+z1,-190,-180);
         }
         if(hh2==1)
         {
         	g.drawString("x2="+z2,-190,-160);
         }
         if(hh3==1)
         {
         	g.drawString("x3="+z3,-190,-140);
         }
         
     }

}