双向链表

1. 节点类

package com.linkedlist.doublelinkedlist;

public class Node {
    public int no;
    public String name;
    public Node next;
    public Node pre;

    public Node() {
    }

    public Node(int no, String name){
        this.no = no;
        this.name = name;
    }

    @Override
    public String toString() {
        return "Node{" +
                "no=" + no +
                ", name='" + name + '\'' +
                '}';
    }
}

2. 链表类

package com.linkedlist.doublelinkedlist;

public class DoubleLinkedList {
    final Node head = new Node();

    public void add(Node node){
        Node temp = head;
        while(true){
            if(temp.next == null){
                break;
            }
            temp = temp.next;
        }
        temp.next = node;
        node.pre = temp;
    }

    public void addOrderByAsc(Node node){
        Node temp = head;
        boolean flag = false;
        while(true){
            if(temp.next == null){
                break;
            }
            if(temp.next.no > node.no){
                break;
            }else if(temp.next.no == node.no){
                flag = true;
                break;
            }
            temp = temp.next;
        }
        if(flag){
            System.out.println("节点已经存在!");
        }else{
            node.next = temp.next;
            //判断是否在链表结尾
            if(temp.next != null){
                temp.next.pre = node;
            }
            node.pre = temp;
            temp.next = node;
        }

    }


    public void list(){
        if(head.next == null){
            System.out.println("双向链表为空！");
            return;
        }
        Node temp = head.next;
        while(temp != null){
            System.out.println(temp);
            temp = temp.next;
        }
    }

    public void update(Node node){
        if(head.next == null){
            System.out.println("该双向链表为空！");
            return;
        }
        Node temp = head.next;
        boolean flag = false;
        while(temp != null){
            if(temp.no == node.no){
                flag = true;
                break;
            }
            temp = temp.next;
        }
        if(flag){
            temp.name = node.name;
        }else{
            System.out.println("该节点不存在!");
        }
    }


    public void del(int no){
        if(head.next == null){
            System.out.println("该双向链表为null");
            return;
        }
        Node temp = head.next;
        boolean flag = false;
        while(temp != null){
            if(temp.no == no){
                flag = true;
                break;
            }
            temp = temp.next;
        }
        if(flag){
            temp.pre.next = temp.next;
            if(temp.next != null){
                temp.next.pre = temp.pre;
            }
        }else{
            System.out.println("节点不存在！");
        }
    }
}