题目描述 Farmer John has N barren pastures (2 <= N <= 100,000) connected by N-1 bidirectional roads, such that there is exactly one path between any two pastures. Bessie, a cow who loves her grazing time, often complains about how there is no grass on t…
表示看不太清. 概括题意 树上维护区间修改与区间和查询. 很明显树剖裸题,切掉,细节处错误T了好久 TAT 代码 #include<cstdio> #include<cstdlib> #include<cstring> #include<iostream> #define int long long #define R register #define ls o<<1 #define rs o<<1|1 #define N 50000…
题目描述 Farmer John has N barren pastures (2 <= N <= 100,000) connected by N-1 bidirectional roads, such that there is exactly one path between any two pastures. Bessie, a cow who loves her grazing time, often complains about how there is no grass on t…
题目描述 Farmer John has N barren pastures (2 <= N <= 100,000) connected by N-1 bidirectional roads, such that there is exactly one path between any two pastures. Bessie, a cow who loves her grazing time, often complains about how there is no grass on t…
题目描述 Farmer John has N barren pastures (2 <= N <= 100,000) connected by N-1 bidirectional roads, such that there is exactly one path between any two pastures. Bessie, a cow who loves her grazing time, often complains about how there is no grass on t…
<题目链接> 题目大意: 有一棵点数为 N 的树,以点 1 为根,且树点有权值.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 . 操作 3 :询问某个节点 x 到根的路径中所有点的点权和. Input 第一行包含两个整数 N, M .表示点数和操作数.接下来一行 N 个整数,表示树中节点的初始权值.接下来 N-1 行每行三个正整数 fr, to , 表示该树中存在一条边 (fr, to) .再…
