hanio.java

一个自动演示的汉诺塔JAVA小程序

import javax.swing.*; 
import java.awt.geom.*; 
import java.awt.event.*; 
import java.awt.*; 
public class Hanio extends JApplet implements ActionListener, Runnable 
{ 
 /** 
*diskNum是盘子的数量 
*/ 
 private int diskNum ; 
 /** 
*各个组件的句柄 
*/ 
 private JButton begin, stop; 
 private JLabel lDiskNum; 
 private JTextField text; 
 JPanel pane; 
 /** 
*定义一个线程句柄 
*/ 
 private Thread animate; 
 /** 
*定义a,b,c三个柱子上是否有盘子，有哪些盘子 
*/ 
 private int adisk[]; 
 private int bdisk[]; 
 private int cdisk[]; 
 public void init() 
 { 
   
  Container content = getContentPane(); 
  content.setLayout(new BorderLayout()); 
  lDiskNum = new JLabel("盘子的数目"); 
   
  text = new JTextField(8); 
   
  begin = new JButton("开始"); 
  begin.addActionListener(this); 
   
  stop = new JButton("停止"); 
  stop.addActionListener(this); 
   
  pane = new JPanel(); 
  pane.setLayout(new FlowLayout()); 
  pane.add(lDiskNum); 
  pane.add(text); 
  pane.add(begin); 
  pane.add(stop); 
  content.add(pane, BorderLayout.SOUTH); 
   
 } 
 public void paint(Graphics g) 
 { 
  Graphics2D g2D = (Graphics2D)g; 
  Ellipse2D.Double ellipse; 
  g2D.setPaint(getBackground()); 
  if(adisk != null) 
  { 
   /** 
*消除以前画的盘子 
*/ 
   for(int j=adisk.length, i=0; --j>=0; i++ ) 
   { 
    ellipse = new Ellipse2D.Double(20+i*5, 180-i*10, 180-i*10, 20); 
    g2D.fill(ellipse); 
    ellipse = new Ellipse2D.Double(220+i*5, 180-i*10, 180-i*10, 20); 
    g2D.fill(ellipse); 
    ellipse = new Ellipse2D.Double(420+i*5, 180-i*10, 180-i*10, 20); 
    g2D.fill(ellipse); 
    
   } 
   drawEllipse(g, 20, adisk);//画A组盘子 
   drawEllipse(g, 220, bdisk);//画B组盘子 
   drawEllipse(g, 420, cdisk);//画C组盘子 
    
  } 
  pane.repaint();  
 } 
 public void update(Graphics g) 
 { 
  paint(g); 
 } 
 /**画出椭圆代表盘子，g是图形环境，x是最下面的盘子的横坐标， 
*arr是柱子数组 
*/ 
 public void drawEllipse(Graphics g,int x,int arr[]) 
 { 
  Graphics2D g2D = (Graphics2D)g; 
  Ellipse2D.Double ellipse; 
  g2D.setPaint(Color.gray); 
  g2D.draw(new Line2D.Double(x+90, 10, x+90, 180)); 
  for(int j=arr.length, i=0; --j>=0; i++ ) 
   if(arr[j] != 0) 
   { 
    if(i%2 == 0) 
     g2D.setPaint(Color.blue); 
    else 
     g2D.setPaint(Color.red); 
    ellipse = new Ellipse2D.Double(x+i*5, 180-i*10, 180-i*10, 20); 
    g2D.fill(ellipse); 
   } 
 } 
 public void actionPerformed(ActionEvent e) 
 { 
  String command = e.getActionCommand(); 
  if(command.equals("开始")) 
  { 
   /** 
*进行初始化，开始的时候只有a柱子上有盘子，其他柱子都没有 
*/ 
   diskNum = Integer.parseInt(text.getText()); 
    
   adisk = new int[diskNum]; 
   for(int i=0; i<adisk.length; i++) 
    adisk[i] = 1; 
   bdisk = new int[diskNum]; 
   for(int k=0; k<bdisk.length; k++) 
    bdisk[k] = 0; 
   cdisk = new int[diskNum]; 
   for(int i=0; i<cdisk.length; i++) 
    cdisk[i] = 0; 
   repaint(); 
   if(animate == null || !animate.isAlive())//创建一个线程 
   { 
    animate = new Thread(this); 
    animate.start(); 
   } 
  } 
  if(command.equals("停止")) 
  { 
   for(int k=0; k<bdisk.length; k++) 
    bdisk[k] = 0; 
   for(int i=0; i<cdisk.length; i++) 
    cdisk[i] = 0; 
   repaint(); 
   text.setText(""); 
   animate = null; 
  } 
 } 
 /** 
*线程方法，在此调用汉诺塔执行移动盘子操作 
*/ 
 public void run() 
 { 
  hanio(diskNum, 'A', 'B', 'C'); 
  repaint(); 
 } 
 /** 
*汉诺塔递规调用程序，n是盘子的数量，A，B，C分别代表三个柱子 
*/ 
 public void hanio(int n, char A, char B, char C) 
 { 
  if(n > 1) 
  { 
   hanio(n-1, A, C, B); 
   pause();//停顿几秒在执行 
   switch(A) 
   { 
    case 'A':adisk[n-1] = 0;break; 
    case 'B':bdisk[n-1] = 0;break; 
    case 'C':cdisk[n-1] = 0;break; 
    default:break; 
   } 
   switch(C) 
   { 
    case 'A':adisk[n-1] = 1;break; 
    case 'B':bdisk[n-1] = 1;break; 
    case 'C':cdisk[n-1] = 1;break; 
    default:break; 
   } 
   repaint(); 
   hanio(n-1, B, A, C); 
  } 
  pause(); 
switch(A) 
  { 
   case 'A':adisk[n-1] = 0;break; 
   case 'B':bdisk[n-1] = 0;break; 
   case 'C':cdisk[n-1] = 0;break; 
   default:break; 
  } 
  switch(C) 
  { 
   case 'A':adisk[n-1] = 1;break; 
   case 'B':bdisk[n-1] = 1;break; 
   case 'C':cdisk[n-1] = 1;break; 
   default:break; 
  } 
  repaint(); 
   
 } 

  
 /** 
*每隔半妙钟移动一个盘子 
*/ 
 public void pause() 
 { 
  try{ 
   Thread.sleep(500);//可以修改此值加快盘子移动的速度 
  }catch(InterruptedException e){} 
 } 
}