题目传送： ​​https://leetcode.cn/problems/lru-cache/​​

运行效率：

Leetcode146. LRU 缓存_java


代码如下：

class LRUCache extends LinkedHashMap<Integer, Integer>{
    private int capacity;
    
    public LRUCache(int capacity) {
        //LinkedHashMap有五个构造器:但是可以把accessOrDER 改成true的，只有
        //  LinkedHashMap(int initialCapacity,float loadFactor, boolean accessOrder) 这个构造器
        //  所以负载因子必须要写,而要写负载因子，0.75比较合适,所以就是这样
        super(capacity, 0.75F, true);
        this.capacity = capacity;
    }

    public int get(int key) {
        return super.getOrDefault(key, -1);
    }

    public void put(int key, int value) {
        super.put(key, value);
    }

    @Override
    protected boolean removeEldestEntry(Map.Entry<Integer, Integer> eldest) {
        return size() > capacity; 
    }
}



/**
 * 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);
 */