2019The Preliminary Contest for ICPC China Nanchang National Invitational

The Preliminary Contest for ICPC China Nanchang National Invitational

题解：

　　[1]:https://www.cnblogs.com/songorz/p/10743353.html

题目一览表	考察知识点
I. Max answer	单调栈+暴力？？
J. Distance on the tree	树链剖分
M. Subsequence	思维？？