再插一嘴：**倍增 LCA** 可过。
by Cat_shao @ 2022-01-20 23:52:15
tlqtj（？
by Fishmaster @ 2022-01-21 06:57:04
@[摸鱼_](/user/531258) 不算吧
by Xeqwq @ 2022-01-21 08:10:43