题解 | #设计LRU缓存结构#

import java.util.*;


public class Solution {
    Map<Integer, Integer> map;
    int capacity;
    /**
     * lru design
     * @param operators int整型二维数组 the ops
     * @param k int整型 the k
     * @return int整型一维数组
     */
    public int[] LRU (int[][] operators, int k) {
        // write code here
        this.capacity = k;
        map = new LinkedHashMap<Integer, Integer>(capacity, 0.75f, true){

            protected boolean removeEldestEntry(Map.Entry eldest){
                return size()>capacity;
            }
        };
        
        List<Integer> res = new ArrayList<>();
        for(int i = 0; i< operators.length;i++){
            if(operators[i][0] == 1){
                set(operators[i][1], operators[i][2]);
            }else{
                res.add(get(operators[i][1]));
            }
        }
        
        return res.stream().mapToInt(Integer::valueOf).toArray();
    }
    
    public void set(int key, int val){
        map.put(key, val);
    }
    
    public Integer get(int key){
        return map.getOrDefault(key, -1);
    }
}