package Queue;

public class LinkQueue {

	Node front;
	Node rear;
	Node head;
	
	public void init() {
	
		head=new Node();
		front=new Node();
		rear=new Node();
		
		front=head;
		rear=head;
		
	}
	
	//入队
	public void enQueue(Object e) {
		Node node=new Node();
		node.data=e;
		
		//第一次入队
		if(rear==head) {
			head.next=node;
			front.next=node;
			rear=node;
		}else {
			rear.next=node;
			rear=node;
		}
	}
	
	public void deQueue() {
		if(rear==head) {
			//队列为空
			return;
		}else {
			//队中只有一个元素
			if(front.next==rear) {
				rear=front;
			}else {
				front.next=front.next.next;
			}
		}
	}
	
	public void printQueue() {
		Node temp=head;
		while(temp!=rear) {
			System.out.println(temp.next.data);
			temp=temp.next;
		}
	}
	
	class Node{
		Object data;
		Node next;
	}
}

package Queue;

public class TestQueue {

	public static void main(String[] args) {
		// TODO Auto-generated method stub

		LinkQueue qu=new LinkQueue();
		qu.init();
		qu.enQueue("ddd");
		qu.enQueue(8);
		qu.enQueue("ct");
		qu.enQueue(99);
		//qu.deQueue();
		qu.printQueue();
	}

}

package linkStack;

public class LinkStack {

	Node base;
	Node top;
	
	public void init() {
		base=new Node();
		top=new Node();
		
		base.data=null;
		base.next=null;
		
		top.data=null;
		top.next=base;
	}
	
	//入栈
	public void push(String e) {
		Node node=new Node();
		node.data=e;
		
		//第一次入栈
		if(top.next==base) {
			node.next=base;
			top.next=node;
		}else {
			node.next=top.next;
			top.next=node;
		}
	}
	
	//出栈
	public void pop() {
		if(top.next==base)
        {
            System.out.println("栈中没有元素！");
        }else
        {
            //System.out.println("出栈操作"+top.next.data);
            top.next=top.next.next;
        }
	}
	
	public void printNode() {
		Node temp=top;
		while(temp.next!=base) {
			temp=temp.next;
			System.out.println(temp.data);
		}
	}
	
	class Node{
		String data;
		Node next;
	}
}

package linkStack;

public class TestStack {

	public static void main(String[] args) {
		// TODO Auto-generated method stub

		LinkStack stack=new LinkStack();
		stack.init();
		stack.push("abcd");
		stack.push("fff");
		stack.push("gggg");
		stack.push("eeee");
		stack.pop();
		stack.printNode();
	}

}

package sort;

public class SelectionSort {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		int [] a= {99,45,67,12,84,59,32};
		selectionSort(a);
		printArr(a);
	}
	
	public static void selectionSort(int [] arr) {
		//选择小的，从小排到大
		int min;//min记录最小值的下标
		
		for(int i=0;i<arr.length-1;i++) {//比arr.length-1趟
			min=i;
			for(int j=i;j<arr.length;j++) {
				if(arr[j]<arr[min]) {
					min=j;//记录下标
				}
			}
			
			//把最小的排到数组前
			int temp=arr[i];
			arr[i]=arr[min];
			arr[min]=temp;			
		}
	}
	
	public static void printArr(int [] a) {
		for(int i=0;i<a.length;i++) {
			System.out.print(a[i]+" ");
		}
	}
}

public interface MediaPlayer {
   public void play(String audioType, String fileName);
}

public interface AdvancedMediaPlayer { 
   public void playVlc(String fileName);
   public void playMp4(String fileName);
}

public class VlcPlayer implements AdvancedMediaPlayer{
   @Override
   public void playVlc(String fileName) {
      System.out.println("Playing vlc file. Name: "+ fileName);      
   }
 
   @Override
   public void playMp4(String fileName) {
      //什么也不做
   }
}

public class Mp4Player implements AdvancedMediaPlayer{
 
   @Override
   public void playVlc(String fileName) {
      //什么也不做
   }
 
   @Override
   public void playMp4(String fileName) {
      System.out.println("Playing mp4 file. Name: "+ fileName);      
   }
}

public class MediaAdapter implements MediaPlayer {
 
   AdvancedMediaPlayer advancedMusicPlayer;
 
   public MediaAdapter(String audioType){
      if(audioType.equalsIgnoreCase("vlc") ){
         advancedMusicPlayer = new VlcPlayer();       
      } else if (audioType.equalsIgnoreCase("mp4")){
         advancedMusicPlayer = new Mp4Player();
      }  
   }
 
   @Override
   public void play(String audioType, String fileName) {
      if(audioType.equalsIgnoreCase("vlc")){
         advancedMusicPlayer.playVlc(fileName);
      }else if(audioType.equalsIgnoreCase("mp4")){
         advancedMusicPlayer.playMp4(fileName);
      }
   }
}

public class AudioPlayer implements MediaPlayer {
   MediaAdapter mediaAdapter; 
 
   @Override
   public void play(String audioType, String fileName) {    
 
      //播放 mp3 音乐文件的内置支持
      if(audioType.equalsIgnoreCase("mp3")){
         System.out.println("Playing mp3 file. Name: "+ fileName);         
      } 
      //mediaAdapter 提供了播放其他文件格式的支持
      else if(audioType.equalsIgnoreCase("vlc") 
         || audioType.equalsIgnoreCase("mp4")){
         mediaAdapter = new MediaAdapter(audioType);
         mediaAdapter.play(audioType, fileName);
      }
      else{
         System.out.println("Invalid media. "+
            audioType + " format not supported");
      }
   }   
}

public class AdapterPatternDemo {
   public static void main(String[] args) {
      AudioPlayer audioPlayer = new AudioPlayer();
 
      audioPlayer.play("mp3", "beyond the horizon.mp3");
      audioPlayer.play("mp4", "alone.mp4");
      audioPlayer.play("vlc", "far far away.vlc");
      audioPlayer.play("avi", "mind me.avi");
   }
}

Playing mp3 file. Name: beyond the horizon.mp3
Playing mp4 file. Name: alone.mp4
Playing vlc file. Name: far far away.vlc
Invalid media. avi format not supported

import java.util.ArrayList;
import java.util.List;
 
public class Subject {
   
   private List<Observer> observers 
      = new ArrayList<Observer>();
   private int state;
 
   public int getState() {
      return state;
   }
 
   public void setState(int state) {
      this.state = state;
      notifyAllObservers();
   }
 
   public void attach(Observer observer){
      observers.add(observer);      
   }
 
   public void notifyAllObservers(){
      for (Observer observer : observers) {
         observer.update();
      }
   }  
}

public abstract class Observer {
   protected Subject subject;
   public abstract void update();
}

public class BinaryObserver extends Observer{
 
   public BinaryObserver(Subject subject){
      this.subject = subject;
      this.subject.attach(this);
   }
 
   @Override
   public void update() {
      System.out.println( "Binary String: " 
      + Integer.toBinaryString( subject.getState() ) ); 
   }
}

public class OctalObserver extends Observer{
 
   public OctalObserver(Subject subject){
      this.subject = subject;
      this.subject.attach(this);
   }
 
   @Override
   public void update() {
     System.out.println( "Octal String: " 
     + Integer.toOctalString( subject.getState() ) ); 
   }
}

public class HexaObserver extends Observer{
 
   public HexaObserver(Subject subject){
      this.subject = subject;
      this.subject.attach(this);
   }
 
   @Override
   public void update() {
      System.out.println( "Hex String: " 
      + Integer.toHexString( subject.getState() ).toUpperCase() ); 
   }
}

public class ObserverPatternDemo {
   public static void main(String[] args) {
      Subject subject = new Subject();
 
      new HexaObserver(subject);
      new OctalObserver(subject);
      new BinaryObserver(subject);
 
      System.out.println("First state change: 15");   
      subject.setState(15);
      System.out.println("Second state change: 10");  
      subject.setState(10);
   }
}

First state change: 15
Hex String: F
Octal String: 17
Binary String: 1111
Second state change: 10
Hex String: A
Octal String: 12
Binary String: 1010

public interface Strategy {
   public int doOperation(int num1, int num2);
}

public class OperationAdd implements Strategy{
   @Override
   public int doOperation(int num1, int num2) {
      return num1 + num2;
   }
}

public class OperationSubstract implements Strategy{
   @Override
   public int doOperation(int num1, int num2) {
      return num1 - num2;
   }
}

public class OperationMultiply implements Strategy{
   @Override
   public int doOperation(int num1, int num2) {
      return num1 * num2;
   }
}

public class Context {
   private Strategy strategy;
 
   public Context(Strategy strategy){
      this.strategy = strategy;
   }
 
   public int executeStrategy(int num1, int num2){
      return strategy.doOperation(num1, num2);
   }
}

public class StrategyPatternDemo {
   public static void main(String[] args) {
      Context context = new Context(new OperationAdd());    
      System.out.println("10 + 5 = " + context.executeStrategy(10, 5));
 
      context = new Context(new OperationSubstract());      
      System.out.println("10 - 5 = " + context.executeStrategy(10, 5));
 
      context = new Context(new OperationMultiply());    
      System.out.println("10 * 5 = " + context.executeStrategy(10, 5));
   }
}

10 + 5 = 15
10 - 5 = 5
10 * 5 = 50

public interface Shape {
   void draw();
}

public class Rectangle implements Shape {
 
   @Override
   public void draw() {
      System.out.println("Shape: Rectangle");
   }
}

public class Circle implements Shape {
 
   @Override
   public void draw() {
      System.out.println("Shape: Circle");
   }
}

public abstract class ShapeDecorator implements Shape {
   protected Shape decoratedShape;
 
   public ShapeDecorator(Shape decoratedShape){
      this.decoratedShape = decoratedShape;
   }
 
   public void draw(){
      decoratedShape.draw();
   }  
}

public class RedShapeDecorator extends ShapeDecorator {
 
   public RedShapeDecorator(Shape decoratedShape) {
      super(decoratedShape);     
   }
 
   @Override
   public void draw() {
      decoratedShape.draw();         
      setRedBorder(decoratedShape);
   }
 
   private void setRedBorder(Shape decoratedShape){
      System.out.println("Border Color: Red");
   }
}

public class DecoratorPatternDemo {
   public static void main(String[] args) {
 
      Shape circle = new Circle();
 
      Shape redCircle = new RedShapeDecorator(new Circle());
 
      Shape redRectangle = new RedShapeDecorator(new Rectangle());
      System.out.println("Circle with normal border");
      circle.draw();
 
      System.out.println("\nCircle of red border");
      redCircle.draw();
 
      System.out.println("\nRectangle of red border");
      redRectangle.draw();
   }
}

Circle with normal border
Shape: Circle

Circle of red border
Shape: Circle
Border Color: Red

Rectangle of red border
Shape: Rectangle
Border Color: Red

public abstract class Game {
   abstract void initialize();
   abstract void startPlay();
   abstract void endPlay();
 
   //模板
   public final void play(){
 
      //初始化游戏
      initialize();
 
      //开始游戏
      startPlay();
 
      //结束游戏
      endPlay();
   }
}

public class Cricket extends Game {
 
   @Override
   void endPlay() {
      System.out.println("Cricket Game Finished!");
   }
 
   @Override
   void initialize() {
      System.out.println("Cricket Game Initialized! Start playing.");
   }
 
   @Override
   void startPlay() {
      System.out.println("Cricket Game Started. Enjoy the game!");
   }
}

public class Football extends Game {
 
   @Override
   void endPlay() {
      System.out.println("Football Game Finished!");
   }
 
   @Override
   void initialize() {
      System.out.println("Football Game Initialized! Start playing.");
   }
 
   @Override
   void startPlay() {
      System.out.println("Football Game Started. Enjoy the game!");
   }
}

public class TemplatePatternDemo {
   public static void main(String[] args) {
 
      Game game = new Cricket();
      game.play();
      System.out.println();
      game = new Football();
      game.play();      
   }
}

Cricket Game Initialized! Start playing.
Cricket Game Started. Enjoy the game!
Cricket Game Finished!

Football Game Initialized! Start playing.
Football Game Started. Enjoy the game!
Football Game Finished!