链队列

 

队列接口 IQueue.java

 1 package cn.ftf.ILinkQueue;
 2 
 3 public interface IQueue {
 4     public void clear();
 5     public boolean isEmpty();
 6     public int length();
 7     public Object peek();  //返回队列首元素
 8     public void offer(Object x);  //将元素插入队尾
 9     public Object pool();  //从队首出队
10     public void display();  //遍历队列元素
11 }

经典结点类Node.java

package cn.ftf.ILinkQueue;
/**
 * 节点类
 * 单链表节点类描述
 * @author 房廷飞
 *
 */
public class Node {
    public Object data;  //存放数据值
    public Node next;  //存放后继节点

    
    //无参构造函数
    public Node() {
        this(null,null);
    }
    //只有结点值的构造参数


    public Node(Object data) {
        this(data,null);
    }

    //有结点值和后继结点的构造参数
    public Node(Object data, Node next) {
        super();
        this.data = data;
        this.next = next;
    }
    
    
}

 

链队列的实现类MyLinkQueue.java

 1 package cn.ftf.ILinkQueue;
 2 
 3 public class MyLinkQueue implements IQueue{
 4     private Node first;
 5     private Node last;
 6     
 7     
 8     public MyLinkQueue(){
 9         first=last=null;
10     }
11 
12     @Override
13     public void clear() {
14         first=last=null;
15         
16     }
17 
18     @Override
19     public boolean isEmpty() {
20         // TODO Auto-generated method stub
21         return first==null;
22     }
23 
24     @Override
25     public int length() {
26         int len=0;
27         if(isEmpty()) {
28             return 0;
29         }
30         Node fir=first;
31         while(fir!=null) {
32             fir=fir.next;
33             len++;    
34         }
35         return len;
36     }
37 
38     @Override
39     public Object peek() {  //返回队首元素
40         return first.data;
41     }
42 
43     @Override
44     public void offer(Object x) {  //插入队尾
45         Node n=new Node(x);
46         if(isEmpty()) {
47             first=last=n;
48         }
49         last.next=n;
50         last=n;
51         
52     }
53 
54     @Override
55     public Object pool() {  //从队首出队，并返回
56         Node n=first;
57         first=first.next;
58         return n.data;
59     }
60 
61     @Override
62     public void display() {
63         if(!isEmpty()) {
64             Node fir=first;
65             while(fir!=null) {
66                 System.out.println(fir.data);
67                 fir=fir.next;
68             }
69         }    
70     }
71     
72 public static void main(String[] args) {
73     MyLinkQueue m=new MyLinkQueue();
74     m.offer("hello");
75     m.offer("word");
76     m.offer("!!!");
77     m.display();
78     System.out.println("--------------");
79     m.pool();
80     m.display();
81     System.out.println(m.length());
82     m.clear();
83     System.out.println("--------------");
84     m.display();
85     }
86 
87 }

 

posted @ 2019-08-06 21:42  codeFlyer  阅读(195)  评论(0)    收藏  举报