树分治,设当前树的分治中心为x,其子树分治中心为y,则设father[y]=x,分治下去则可以得到一颗重心树,而且树的深度是logn. 询问操作(x,d),只需要查询重心树上x到重心树根节点上的节点的累加和.假设当前节点是y,那么节点y可以贡献的答案是那些以y为分治中心且到y距离为d-dis(x,y)的节点的总和.当然这样可能会出现重复的情况,重复情况只会出现在包含x的那颗子树上,因此减掉即可.修改操作类似.复杂度O(nlognlogn) 代码 #include<cstdio> #includ…

bobo has a tree, whose vertices are conveniently labeled by 1,2,…,n. At the very begining, the i-th vertex is assigned with weight w i. There are q operations. Each operations are of the following 2 types: Change the weight of vertex v into x (denote…

题意 给定一棵 \(n\) 个节点的树,每个节点有点权.完成 \(q\) 个操作--操作分两种:修改点 \(x\) 的点权.查询与 \(x\) 距离小于等于 \(d\) 的权值总和. \(1 \leq n,q \leq 10^5\) 思路 从最简单的情况分析--只有一次查询.当然一遍 \(O(n)\) 的 \(\text{dfs}\) 可以直接写,不过要用点分治写的话,\(\text{solve}\) 函数直接容斥一下就可以了. 如果多个询问呢?其实在回答关于点 \(x\) 的询问时,其实只需要…

A Simple Tree Problem Time Limit: 3 Seconds      Memory Limit: 65536 KB Given a rooted tree, each node has a boolean (0 or 1) labeled on it. Initially, all the labels are 0. We define this kind of operation: given a subtree, negate all its labels. An…

1. Introduction 1.1. About 1.2. Sphinx features 1.3. Where to get Sphinx 1.4. License 1.5. Credits 1.6. History 2. Installation 2.1. Supported systems 2.2. Compiling Sphinx from source 2.2.1. Required tools 2.2.2. Compiling on Linux 2.2.3. Known comp…

对线段树的区间更新有了初步的了解... A Simple Tree Problem Time Limit: 3 Seconds      Memory Limit: 65536 KB Given a rooted tree, each node has a boolean (0 or 1) labeled on it. Initially, all the labels are 0. We define this kind of operation: given a subtree, negat…

Description Given a rooted tree, each node has a boolean (0 or 1) labeled on it. Initially, all the labels are 0. We define this kind of operation: given a subtree, negate all its labels. And we want to query the numbers of 1's of a subtree. Input Mu…

Tamref love random numbers, but he hates recurrent relations, Tamref thinks that mainstream random generators like the linear congruent generator suck. That's why he decided to invent his own random generator. As any reasonable competitive programmer…

A Simple Tree Problem Time Limit: 3000ms Memory Limit: 65536KB This problem will be judged on ZJU. Original ID: 368664-bit integer IO format: %lld      Java class name: Main Prev Submit Status Statistics Discuss Next Type: None   None Graph Theory 2-…

I. A Simple Tree Problem Time Limit: 3000ms Memory Limit: 65536KB 64-bit integer IO format: %lld      Java class name: Main   Given a rooted tree, each node has a boolean (0 or 1) labeled on it. Initially, all the labels are 0. We define this kind of…