D. Happy Tree Party     Bogdan has a birthday today and mom gave him a tree consisting of n vertecies. For every edge of the tree i, some number xi was written on it. In case you forget, a tree is a connected non-directed graph without cycles. After…

题目链接 题意:就是给你一颗这样的树,用一个$y$来除以两点之间每条边的权值,比如$3->7$,问最后的y的是多少,修改操作是把权值变成更小的. 这个$(y<=10^{18})$除的权值如果是$>=2$,那么最多除60几次就变成0了,问题关键是路径上会有好多1存在,这时候我们可以用并查集把他们并到一块,这样就能跳着查了. 具体查法: 从$u$到$LCA(u,v)$,路径上除一遍. 从$v$到$LCA(u,v)$,路径上除一遍. 修改操作如果变成1,就与前面的点合并. #include &…

D. Happy Tree Party Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/593/problem/D Description Bogdan has a birthday today and mom gave him a tree consisting of n vertecies. For every edge of the tree i, some number xi was w…

C. Propagating tree Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/383/problem/C Description Iahub likes trees very much. Recently he discovered an interesting tree named propagating tree. The tree consists of n nodes numb…

C. Propagating tree Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/383/problem/C Description Iahub likes trees very much. Recently he discovered an interesting tree named propagating tree. The tree consists of n nodes numb…

Count on a tree SPOJ 10628 主席树+LCA(树链剖分实现)(两种存图方式) 题外话,这是我第40篇随笔,纪念一下.<(￣︶￣)↗[GO!] 题意 是说有棵树,每个节点上都有一个值,然后让你求从一个节点到另一个节点的最短路上第k小的值是多少. 解题思路 看到这个题一想以为是树链剖分+主席树,后来写着写着发现不对,因为树链剖分我们分成了一小段一小段,这些小段不能合并起来求第k小,所以这个想法不对.奈何不会做,查了查题解,需要用LCA(最近公共祖先),然后根据主席树具有区间加…

Water Tree 给出一棵树,有三种操作: 1 x:把以x为子树的节点全部置为1 2 x:把x以及他的所有祖先全部置为0 3 x:询问节点x的值 分析: 昨晚看完题,马上想到直接树链剖分,在记录时间戳时需要记录一下出去时的时间戳,然后就是很裸很裸的树链剖分了. 稳稳的黄名节奏,因为一点私事所以没做导致延迟了 (ps:后来想了一下,不用树链剖分直接dfs序维护也行...) #include <set> #include <map> #include <list> #i…

D. Water Tree time limit per test 4 seconds memory limit per test 256 megabytes input standard input output standard output Mad scientist Mike has constructed a rooted tree, which consists of n vertices. Each vertex is a reservoir which can be either…

简单的树链剖分+线段树 #include<bits\stdc++.h> using namespace std; #define pb push_back #define lson root<<1,l,midd #define rson root<<1|1,midd+1,r ; vector<int>g[M]; ],lazy[M<<],top[M],son[M],fa[M],sz[M],dfn[M],to[M],deep[M],cnt,n; vo…

题目:http://codeforces.com/contest/504/problem/E 树链剖分,把重链都接起来,且把每条重链的另一种方向的也都接上,在这个 2*n 的序列上跑后缀数组. 对于询问,把两条链拆成一些重链的片段,然后两个指针枚举每个片段,用后缀数组找片段与片段的 LCP ,直到一次 LCP 的长度比两个片段的长度都小,说明两条链的 LCP 截止于此. 把重链放到序列上其实就是把 dfn 作为序列角标. 不太会实现,就借鉴(抄)了别人的代码.之后要多多回顾. #include<…