LeetCode 146 LRU Cache(双方向チェーンmap)

Design and implement a data structure for Least Recently Used cache.It shound support the follwing operation:  get and  put.get(key) - Get the value of the key if the key exists in the cache,otherswise return-1.put(key, value) - Set or insert the value if the key is not already present.When the cache reached its capacity,it Shuld invalidate the least recently used ite before inserting a new ite.
Followw up:Could you do both operation in O(1) time complexity
Example:

LRUCache cache = new LRUCache( 2 /* capacity */ );

cache.put(1, 1);
cache.put(2, 2);
cache.get(1);       // returns 1
cache.put(3, 3);    // evicts key 2
cache.get(2);       // returns -1 (not found)
cache.put(4, 4);    // evicts key 1
cache.get(1);       // returns -1 (not found)
cache.get(3);       // returns 3
cache.get(4);       // returns 4

テーマリンク:https://leetcode.com/problems/lru-cache/
題目分析:LRU Cache、題名は効率的な挿入削除をサポートする必要があります.双方向チェーンを使うと考えやすくなります.
時間は77.45%を下して、空間は100%を打ち負かします.

class LRUCache {
    
    public class DoublyListNode {
        int key;
        int value;
        DoublyListNode prev;
        DoublyListNode next;

        DoublyListNode(int key, int value) {
            this.key = key;
            this.value = value;
        }
    }
    
    public int maxCapacity;
    public int curCapacity;
    public HashMap nodeMap;
    DoublyListNode head;
    DoublyListNode tail;

    public LRUCache(int capacity) {
        this.maxCapacity = capacity;
        this.nodeMap = new HashMap<>();
    }
    
    public int get(int key) {
        if (!nodeMap.containsKey(key)) {
            return -1;
        }

        setHead(nodeMap.get(key));
        //System.out.println("get head key = " + this.head.key + " tail key = " + this.tail.key);
        return nodeMap.get(key).value;      
    }
    
    public void put(int key, int value) {
        if (!nodeMap.containsKey(key)) {
            DoublyListNode node = new DoublyListNode(key, value);
            nodeMap.put(key, node);
            insert(node);
            setHead(node);
            this.curCapacity++;
            if (this.curCapacity > this.maxCapacity) {
                deleteTail();
            }
        } else {
            nodeMap.get(key).value = value;
            setHead(nodeMap.get(key));
        }

        //System.out.println("put head key = " + this.head.key + " tail key = " + this.tail.key);
    }
    
    public void insert(DoublyListNode node) {
        if (this.tail == null) {
            this.tail = node;
            return;
        }
        
        node.prev = this.tail;
        node.next = null;
        this.tail.next = node;
        this.tail = node;
    }
    
    public void deleteTail() {
        nodeMap.remove(this.tail.key);
        this.tail.prev.next = null;
        this.tail = this.tail.prev;
    }
    
    public void setHead(DoublyListNode node) {
        if (this.head == null) {
            this.head = node;
            return;
        }
        
        if (node == this.head) {
            return;
        } else if (node == this.tail) {
            this.tail.prev.next = null;
            this.tail = this.tail.prev;
        } else {
            node.prev.next = node.next;
            node.next.prev = node.prev;
        }
        
        node.prev = null;
        node.next = this.head;
        this.head.prev = node;
        this.head = node;
    }
}

/**
 * Your LRUCache object will be instantiated and called as such:
 * LRUCache obj = new LRUCache(capacity);
 * int param_1 = obj.get(key);
 * obj.put(key,value);
 */