LRU Cache

LRU Cache

18%

Accepted

Design and implement a data structure for Least Recently Used (LRU) cache. It should support the following operations: get and set.

get(key) - Get the value (will always be positive) of the key if the key exists in the cache, otherwise return -1.
set(key, value) - Set or insert the value if the key is not already present. When the cache reached its capacity, it should invalidate the least recently used item before inserting a new item.

public class Solution {

    // @param capacity, an integer

    int capacity;

    LinkedHashMap<Integer, Integer> map;

    public Solution(int capacity) {

        // write your code here

        map = new LinkedHashMap<Integer, Integer>();

        this.capacity = capacity;

    }

    // @return an integer

    public int get(int key) {

        // write your code here

        if(map.containsKey(key)){

            int val = map.get(key);

            map.remove(key);

            map.put(key, val);

            return val;

        }

        return -1;

    }

    // @param key, an integer

    // @param value, an integer

    // @return nothing

    public void set(int key, int value) {

        // write your code here

        if(map.containsKey(key)){

            map.remove(key);

            map.put(key, value);

            return;

        }

        if (map.size() == capacity){

            for(int first : map.keySet()){

                map.remove(first);

                break;

            }

        }

        map.put(key, value);

       

    }

}