双端链表--Java实现

Posted 2020-10-11 sun1993

 1 /*双端链表--比普通链表多了一个指向最后一个节点的引用
 2  * 特点: 链表可以进行尾巴插入--输出顺序和输入顺序一致
 3  *      但是不可以进行尾巴删除因为没有倒数第二节点的引用
 4  * */
 5 public class MyFirstAndLastLinkedList {
 6     public Link first;
 7     public Link last;
 8     
 9     public MyFirstAndLastLinkedList() {
10         first = null;
11         last = null;
12     }
13     
14     public boolean isEmpty(){
15         return first == null;
16     }
17     
18     //头插入的时候注意空链表对last的处理
19     public void insertFirst(int key){
20         Link newLink = new Link(key);
21         if(isEmpty()){
22             last = newLink;
23         }
24         newLink.next = first;
25         first = newLink;
26     }
27     
28     //尾插入的时候注意空链表对first的处理
29     public void insertLast(int key){
30         Link newLink = new Link(key);
31         if(isEmpty()){
32             first = newLink;
33         }
34         else{
35             last.next = newLink;
36         }
37         last = newLink;
38     }
39     
40     //删除注意只有一个节点对last的处理
41     public Link deleteFirst(){
42         Link temp = first;
43         if(first.next == null){
44             last = null;
45         }
46         first = first.next;
47         return temp;
48     }
49     
50     public void displayLinkedList(){//顺链打印
51         //System.out.println("first---to----last");
52         Link current = first;
53         while(current!= null ){
54             current.diaplayLink();
55             System.out.print("");
56             current = current.next;
57         }
58         System.out.println();
59     }
60     
61     //测试该类
62     public static void main(String[] args) {
63         int[] arr = {1,2,3,4,5,6};
64         MyFirstAndLastLinkedList m = new MyFirstAndLastLinkedList();
65         
66         for(int i = 0; i < arr.length; i++){
67             m.insertLast(arr[i]);
68         }
69         m.displayLinkedList();
70         
71         
72     }
73     
74 }