Leetcode-1244.js

/**
 * 1244. Design A Leaderboard
 * https://leetcode-cn.com/problems/design-a-leaderboard/
 */
var Leaderboard = function() {
  this.board = {}
};

/** 
 * @param {number} playerId 
 * @param {number} score
 * @return {void}
 */
Leaderboard.prototype.addScore = function(playerId, score) {
  this.board[playerId] = (this.board[playerId] || 0) + score
};

/** 
 * @param {number} K
 * @return {number}
 */
Leaderboard.prototype.top = function(K) {
  return [...Object.values(this.board)].sort((a, b) => b-a).slice(0, K).reduce((acc, curr) => acc + curr)
};

/** 
 * @param {number} playerId
 * @return {void}
 */
Leaderboard.prototype.reset = function(playerId) {
  delete this.board[playerId]
};

/**
 * Your Leaderboard object will be instantiated and called as such:
 * var obj = new Leaderboard()
 * obj.addScore(playerId,score)
 * var param_2 = obj.top(K)
 * obj.reset(playerId)
 */