[LeetCode] LRU Cache

 
class LRUCache{
    public:
    typedef std::pair<int, int> ENTRY;
    LRUCache(int capacity) {
        max = capacity;
        count = 0;
    }
    
    int get(int key) {
        if(map.find(key)==map.end())
        return -1;
        else
        {
            entry.splice(entry.begin(), entry, map[key]);
            return (map[key])->second;
        }
    }
    
    void set(int key, int value) {
        if(map.find(key)==map.end())
        {
            entry.push_front(ENTRY(key, value));
            map[key] = entry.begin();
            if(++count>max)
            {
                int tmp = entry.back().first;
                entry.erase(--entry.end());
                count--;
                map.erase(tmp);
            }
        }
        else
        {
            entry.splice(entry.begin(), entry, map[key]);
            map[key]->second = value;
        }
    }
    
    int count;
    int max;
    std::list<std::pair<int, int>> entry;
    std::unordered_map<int, std::list<std::pair<int, int>>::iterator> map;
};