Solution -「JOISC 2023」旅行
Desc.Link.给定一棵 $n$ 个节点的树, $m$ 个关键点 $\{a_m\}$, 和 $q$ 次询问 $l_i, r_i$. 每次询问点集 $\{a_l, \dots, a_r\}$ ...
In mathematics you don't understand things, you just get used to them.
In mathematics you don't understand things, you just get used to them.