~~退化成一个点的三角形~~
by HarunluoON @ 2021-12-03 18:36:39
@[LittleWitchGzm](/user/73173) 初始化，不必计较（~~实际上是蒟蒻不会~~）
by Hoks @ 2022-09-04 10:45:58
@[LittleWitchGzm](/user/73173) 为了后续推倒能进行
by wanglexi @ 2023-04-29 23:35:07