解决n个运动员进行循环赛问题(要求:1.每个选手必须与其他n-1个选手各赛一次，2.每个选手一个只能赛一次，当n为偶数时，循环赛进行n-1天。当n时奇树时，循环赛进行n天-N months to resolve the issue of athletes round robin (required: 1. Each player must be consistent with other n-1 months time player of the tournament, 2. Each play