锦标赛冠军算法javascript使用地图？

class Tournament {
  constructor() {
    this.matches = new Map();
  }

  // 添加比赛结果
  addMatch(winner, loser) {
    if (!this.matches.has(winner)) {
      this.matches.set(winner, []);
    }
    this.matches.get(winner).push(loser);
  }

  // 获取冠军
  getChampion() {
    let current = null;
    for (let [key, value] of this.matches) {
      if (current === null || value.length > this.matches.get(current).length) {
        current = key;
      }
    }
    return current;
  }
}

// 示例使用
const tournament = new Tournament();
tournament.addMatch('A', 'B');
tournament.addMatch('C', 'D');
tournament.addMatch('A', 'C');
tournament.addMatch('A', 'E');

console.log(tournament.getChampion()); // 输出 'A'