LRU Cache

class DS {
public:
    int value;
    list<int>::iterator itr;
};
class LRUCache {
public:
    int capacity;
    list<int> Queue;
    unordered_map<int, DS> HashMap;
    LRUCache(int capacity) {
        this->capacity = capacity;
    }
    int get(int key) {
        if(!HashMap.count(key)) {
            return -1;
        }
        int value = HashMap[key].value;
        put(key, value);
        return value;
    }
    void put(int key, int value) {
        if(HashMap.count(key)) {
            Queue.erase(HashMap[key].itr);
            HashMap.erase(key);
        }
        if(Queue.size() == capacity) {
            HashMap.erase(Queue.back());
            Queue.pop_back();
        }
        Queue.push_front(key);
        HashMap[key] = {value, Queue.begin()};
    }
};