package com.exercise.test;

public class Main {
    public static void main(String[] args) {
        Link link = new Link();
        link.add(1);

        link.delete(1);
        link.print();
        System.out.println(link.getSize());
    }
}

class Link{
    private Node root;       //链表头节点
    private Node lastnNode;  //链表尾节点
    private int size;        //链表长度
　　//链表的节点
    class Node{
        private int val;     //节点值
        private Node next;   //节点的后驱
        public Node(int x){
            this.val = x;
        }
        public int getVal(){
            return this.val;
        }
    }
　　//链表中添加新节点，值为x，添加在尾部
    public void add(int x){
        Node node = new Node(x);
        if (this.root == null){
            this.root = node;
            this.size = 1;
            this.lastnNode = this.root;
        }else {
            this.lastnNode.next = node;
            this.lastnNode = node;
            this.size++;
        }
    }
　　//删除链表中值为x的节点
    public int delete(int x){
        if (this.root == null){
            System.out.println("This link is null, please add node!");
            return -1;
        }else {
            Node p = this.root;
            Node flag = new Node(-1);
            flag.next = p;
　　　　　　　//查找链表中值为x的节点　
            while (p.val != x && p != null){
                p = p.next;
                flag = flag.next;
            }
            if (p == null){
                System.out.println("Can not find this node!");
                return -1;
            }
            flag.next = p.next;
　　　　　　　//判断删除的节点是否为尾节点
            if (p == this.lastnNode){
                this.lastnNode = flag;
            } else {
                p.next = null;
            }
　　　　　　　//判断删除的节点是否为头节点
            if (p == this.root){
                this.root = flag.next;
            }
            this.size--;
            return x;
        }
    }
　　//返回该链表节点数
    public int getSize(){
        return this.size;
    }
　　//打印该链表
    public void print(){
        if (this.root != null){
            System.out.print(this.root.getVal());
            Node p = this.root.next;
            while (p != null){
                System.out.print(" ---> " + p.getVal());
                p = p.next;
            }
            System.out.println();
        }else {
            System.out.println("This link is null");
        }
    }
}