准备一些链表和节点的实体，方便后面使用

java代码

/** * @Description:构造一个链表实体，方便后续构造链表 * @Author: lizhouwei * @CreateDate: 2018/4/6 8:46 * @Modify by: * @ModifyDate:*/public class Link {    public Node head;    public DoubleNode dhead;    public void add(int vlaue) {        Node node = new Node(vlaue);        if (head == null) {            head = node;        } else {            node.next = head;            head = node;        }    }    public void addDoubleNode(int vlaue) {        DoubleNode node = new DoubleNode(vlaue);        if (dhead == null) {            dhead = node;        } else {            node.next = dhead;            dhead.pre =node;            dhead = node;        }    }}class Node {    public int vlaue;    public Node next;    public Node(int vlaue) {        this.vlaue = vlaue;    }}class DoubleNode{    public int vlaue;    public DoubleNode pre;    public DoubleNode next;    public DoubleNode(int vlaue) {        this.vlaue = vlaue;    }}