下午打了湘潭邀请赛,好像缓解了一下北京网络赛超强的自闭感.补一下这个图论题.(补了很久) 题意:给你一颗n节点的树,有m个操作,每次向xi和lca(xi,yi)连边,然后每次zi就是对于新的图在删除每一个点后连通块个数的异或和.然后求的是m次操作后x,y的值. 题解:看这个问题看了好久我都完全无从下手,题意也理解了半天,只知道有环prprpr,然后和x到lca这条链上的点有关系.但是感觉怎么都会T,就只能暴力更新.然后就看别人的题解,并且打开了画图软件,首先,对于一颗树每个点删除后产生的联通块个…

其实打返祖边就相当于$x$到祖先这一段点(不包括两端)答案都要减$1$. 然后每个点最多减$1$次$1$. #include <bits/stdc++.h> using namespace std; #define rep(i, a, b) for (int i(a); i <= (b); ++i) #define dec(i, a, b) for (int i(a); i >= (b); --i) #define MP make_pair #define fi first #de…

题意: 给出一棵树以及m,a,b,x0,y0.之后加m条边{(x1,LCA(x1,y1)),(x2,LCA(x2,y2))...(xm,LCA(xm,ym))}.定义z = f(0)^f(1)^...^f(n-1),其中f(i)代表删掉点i的连通块数.则xi = (axi-1+byi-1+z)%n,yi = (bxi-1+ayi-1+z)%n.求xm和ym. 题解: 维护每个点的度数.初始的点的度数即为删掉该点后的连通块数. 第i次加边(xi,LCA(xi,yi))中xi到LCA(xi,yi)的…

题目: Clone an undirected graph. Each node in the graph contains a label and a list of its neighbors. OJ's undirected graph serialization: Nodes are labeled uniquely. We use # as a separator for each node, and , as a separator for node label and each n…

将COMP20003中关于Graph的内容进行总结,内容来自COMP20003,中文术语并不准确,以英文为准. Graph G = {V, E} 顶Vertices V: can contain information 边Edges E (links between vertices): can have direction and/or weight 种类: 有向图(directed graph):边(edge)有方向. 弱有向连接图Weakly connected directed grap…

题意翻译 给出一棵 n 个结点的树,每个结点有一个颜色 c i . 询问 q 次,每次询问以 v 结点为根的子树中,出现次数 ≥k 的颜色有多少种.树的根节点是1. 感谢@elijahqi 提供的翻译 题目描述 You have a rooted tree consisting of n n n vertices. Each vertex of the tree has some color. We will assume that the tree vertices are numbered…

Cutting Tree 题目连接: https://icpcarchive.ecs.baylor.edu/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=4922 Description Tree in graph theory refers to any connected graph (of nodes and edges) which has no simple cycle, while…

B. Destruction of a Tree time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output You are given a tree (a graph with n vertices and n - 1 edges in which it's possible to reach any vertex from any ot…

B. Destruction of a Tree time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output You are given a tree (a graph with n vertices and n - 1 edges in which it's possible to reach any vertex from any ot…

You are given a tree (a graph with n vertices and n - 1 edges in which it's possible to reach any vertex from any other vertex using only its edges). A vertex can be destroyed if this vertex has even degree. If you destroy a vertex, all edges connect…