Problem 2277 Change Time Limit: 2000 mSec Memory Limit : 262144 KB Problem Description There is a rooted tree with n nodes, number from 1-n. Root’s number is 1.Each node has a value ai. Initially all the node’s value is 0. We have q operations. T…
Problem 2082 过路费 Problem Description 有n座城市,由n-1条路相连通,使得任意两座城市之间可达.每条路有过路费,要交过路费才能通过.每条路的过路费经常会更新,现问你,当前情况下,从城市a到城市b最少要花多少过路费. Input 有多组样例,每组样例第一行输入两个正整数n,m(2 <= n<=50000…