摘要：
Problem Description Sandy likes to play with robots. He is going to organize a running competition between his robots. And he is going to give some pr 阅读全文
摘要：
题目链接：https://www.luogu.com.cn/problem/P3178 题目描述 有一棵点数为 N 的树，以点 1 为根，且树点有边权。然后有 M 个操作，分为三种： 操作 1 ：把某个节点 x 的点权增加 a 。 操作 2 ：把某个节点 x 为根的子树中所有点的点权都增加 a 。 阅读全文