@[YuRuochen](/user/658786) https://www.luogu.com.cn/discuss/26214
by XHY20180718 @ 2022-10-28 18:36:08
@[xiehuiying](/user/399475) 因为所以然，我的做法是错的？！
by YuRuochen @ 2022-10-28 18:48:04
@[YuRuochen](/user/658786) 是的。
by XHY20180718 @ 2022-10-28 18:53:31