使用队列和map实现lru

使用队列和map实现

import java.util.*;


public class Solution {
    /**
     * 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
        ArrayList<Integer>list = new ArrayList();

        Queue<int[]> queue = new LinkedList<int[]>();
        Map<Integer, int[]> map = new HashMap();

            for (int i = 0; i < operators.length; i++) {
                //size > k
                if (queue.size() > k) {
                    int[] poll = queue.poll();
                    map.remove(poll[1]);
                }
                //opt == 1
                if (operators[i][0] == 1) {
                    int[] r = map.get(operators[i][1]);
                    if (r != null) {
                        map.remove(operators[i][1]);
                        queue.remove(r);
                    } 
                    map.put(operators[i][1], operators[i]);
                    queue.offer(operators[i]);
                }
                //opt == 2
                if (operators[i][0] == 2) {
                    //有，放result数组
                    int[] r = map.get(operators[i][1]);
                    if (r != null) {
                        queue.remove(r);
                        queue.offer(r);
                        list.add(r[2]); 
                    } else {
                        list.add(-1);
                    }
                }
            }
        int[] result = new int[list.size()];
        for (int i = 0; i < list.size(); i++) {
            result[i] = list.get(i);
        }
        return result;
    }
}