P3128 [USACO15DEC]最大流Max Flow
题目描述
Farmer John has installed a new system of pipes to transport milk between the stalls in his barn (), conveniently numbered . Eac...
COT - Count on a tree
#tree
You are given a tree with N nodes.The tree nodes are numbered from 1 to N.Each node has an integer weight.
We will ask you to perform the follow...