谁能帮我看看这个LRU算法哪错了，，我在牛客上面老是出问题

2021-03-04 12:36:58 238 阅读 AI 写同款 · GEO 优化AI 选题数据监测一键分发 ›

牛客面试必考算法题刷题文章目录设计LRU缓存结构判断链表中是否有环二分查找实现二叉树先序、中序、后序遍历寻找第K大合并有序链表设计LRU缓存结构设计LRU缓存结构，该结构在构造时确定大小，假设大小为K，并有如下两个功能 set(key, value)：将记录(key, value)插入该结构 get(key)：返回key对应的value值 [要求] set和get方法的时间复杂度为O(1) 某个key的set或get操作一旦发生，认为这个key的记录成了最常使用的。当缓存的大小超过K时，移除最不经常使用的记录，即set或g 阅读详情



package cn.yangyt.lru;



import java.util.HashMap;

import java.util.Scanner;



public class Main {



    private final HashMap<Integer, Node> map = new HashMap<>();

    private final Node head = new Node();

    private final Node tail = new Node();

    private final int capacity;

    private int size;



    public Main(int capacity) {

        head.next = tail;

        tail.pre = head;

        this.capacity = capacity;

        size = 0;

    }



    static class Node {

        private int key;

        private int value;

        private Node pre;

        private Node next;



        public Node() {

        }



        public Node(int key, int value) {

            this.key = key;

            this.value = value;

        }



    }



    //双向链表头插法。

    private void addNode(Node node) {

        Node originHead = head.next;

        head.next = node;

        node.pre = head;

        node.next = originHead;

        originHead.pre = node;

    }



    //双向链表删除某个节点

    private void remove(Node node) {

        Node next = node.next;

        Node pre = node.pre;

        pre.next = next;

        next.pre = pre;

        node.pre = null;

        node.next = null;

    }



    public void put(int key, int value) {

        Node node = map.get(key);

        if (node == null) {

            if (size < capacity) {

                size++;

            } else {

                //删除链表尾节点

                Node pre = tail.pre;

                map.remove(pre.key);

                remove(pre);

            }

            Node node1 = new Node(key, value);

            addNode(node1);

            map.put(key, node1);

        } else {

            //将链表中key的value更换

            node.value = value;

            map.put(key,node);

//            node.value = value;

//            remove(node);

//            addNode(node);

        }

    }



    public int get(int key) {

        Node node = map.get(key);

        if (node == null) {

            return -1;

        }

        remove(node);

        addNode(node);

        return node.value;

    }



    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);

        Main lru = new Main(sc.nextInt());

        while (sc.hasNextLine()){

            String str = sc.nextLine();

            String[] c = str.split(" ");

            String m = c[0];

            if("p".equals(m)){

                lru.put(Integer.parseInt(c[1]),Integer.parseInt(c[2]));

            }else if ("g".equals(m)){

                System.out.println(lru.get(Integer.parseInt(c[1])));

            }

        }

        sc.close();

    }

}