# leetcode\_1244

Design a Leaderboard class, which has 3 functions:

addScore(playerId, score): Update the leaderboard by adding score to the given player's score. If there is no player with such id in the leaderboard, add him to the leaderboard with the given score. top(K): Return the score sum of the top K players. reset(playerId): Reset the score of the player with the given id to 0 (in other words erase it from the leaderboard). It is guaranteed that the player was added to the leaderboard before calling this function. Initially, the leaderboard is empty.

Example 1:

Input: \["Leaderboard","addScore","addScore","addScore","addScore","addScore","top","reset","reset","addScore","top"] \[\[],\[1,73],\[2,56],\[3,39],\[4,51],\[5,4],\[1],\[1],\[2],\[2,51],\[3]] Output: \[null,null,null,null,null,null,73,null,null,null,141]

Explanation: Leaderboard leaderboard = new Leaderboard (); leaderboard.addScore(1,73); // leaderboard = \[\[1,73]]; leaderboard.addScore(2,56); // leaderboard = \[\[1,73],\[2,56]]; leaderboard.addScore(3,39); // leaderboard = \[\[1,73],\[2,56],\[3,39]]; leaderboard.addScore(4,51); // leaderboard = \[\[1,73],\[2,56],\[3,39],\[4,51]]; leaderboard.addScore(5,4); // leaderboard = \[\[1,73],\[2,56],\[3,39],\[4,51],\[5,4]]; leaderboard.top(1); // returns 73; leaderboard.reset(1); // leaderboard = \[\[2,56],\[3,39],\[4,51],\[5,4]]; leaderboard.reset(2); // leaderboard = \[\[3,39],\[4,51],\[5,4]]; leaderboard.addScore(2,51); // leaderboard = \[\[2,51],\[3,39],\[4,51],\[5,4]]; leaderboard.top(3); // returns 141 = 51 + 51 + 39;

Constraints:

1 <= playerId, K <= 10000 It's guaranteed that K is less than or equal to the current number of players. 1 <= score <= 100 There will be at most 1000 function calls.

## Solutions

1. **hashmap with treemap**
2. Use hashmap for mapping key to score
3. Use treemap to keep records of decreasing scores.

```cpp
class Leaderboard {
public:
    unordered_map<int, multiset<int>::iterator> m;
    multiset<int, greater<>> scores;
    Leaderboard() {

    }

    void addScore(int playerId, int score) {
        int prescore = 0;
        if (m.count(playerId)) {
            prescore = *m[playerId];
            scores.erase(m[playerId]);
        }
        m[playerId] = scores.insert(prescore + score);
    }

    int top(int K) {
        auto it = scores.begin();
        int res = 0;
        while (K-- && it != scores.end()) {
            res += *it;
            ++it;
        }
        return res;
    }

    void reset(int playerId) {
        scores.erase(m[playerId]);
        m.erase(playerId);
    }
};

/**
 * Your Leaderboard object will be instantiated and called as such:
 * Leaderboard* obj = new Leaderboard();
 * obj->addScore(playerId,score);
 * int param_2 = obj->top(K);
 * obj->reset(playerId);
 */
```