Java之链表的基本操作

1.相关基本操作

//实现链表的基本操作
public class Mysiglelist {//节点类static class ListNode {int val;ListNode next;public ListNode(int data) {this.val = data;}}public ListNode head;// 头插public void addFirst(int data) {ListNode node = new ListNode(data);node.next = head;head = node;}//尾插public void addLast(int data) {ListNode node = new ListNode(data);if(head==null){head=node;return;}ListNode cur = head;while (cur.next != null) {cur = cur.next;}cur.next = node;}//获取链表的长度public int size() {//1.空链表if(head==null){return 0;}//2.非空链表int count=0;ListNode cur = head;while (cur!= null) {cur = cur.next;count++;}return count;}//链表的打印public void show() {ListNode cur = head;while (cur != null) {System.out.print(cur.val+" ");cur = cur.next;}System.out.println();}//是否包含 数据keypublic boolean contains(int key) {ListNode cur = head;while (cur != null) {if(cur.val == key) {return true;}cur = cur.next;}return false;}
}

2.操作的调用

public class Test {public static void main(String[] args) {Mysiglelist mysiglelist=new Mysiglelist();mysiglelist.addFirst(1);mysiglelist.addFirst(2);mysiglelist.addLast(3);mysiglelist.addLast(4);mysiglelist.show();System.out.println(mysiglelist.size());System.out.println(mysiglelist.contains(999));}
}