[hdu4582]DFS spanning tree】的更多相关文章

考虑每一条非树边都连接了祖先和儿子,类似于序列上的问题,从底往上算,当发现如果走到某个环的祖先,且这个环中还没有被选到,那么就将最浅的那条边贪心选择即可具体实现可以使用bitset维护当前子树的询问,如果这条边选了,那么bitset清空,否则和父亲合并 1 #include<bits/stdc++.h> 2 using namespace std; 3 #define N 2005 4 struct ji{ 5 int nex,to; 6 }edge[N<<1]; 7 bitset…
Problem Description Consider a Depth-First-Search(DFS) spanning tree T of a undirected connected graph G, we define a T-Simple Circle as a path v1, v2, ..., vk (v1 = vk) in G that contains at most one edge which not belongs to the DFS spanning tree T…
E. Minimum spanning tree for each edge   Connected undirected weighted graph without self-loops and multiple edges is given. Graph contains n vertices and m edges. For each edge (u, v) find the minimal possible weight of the spanning tree that contai…
E. Minimum spanning tree for each edge 题目连接: http://www.codeforces.com/contest/609/problem/E Description Connected undirected weighted graph without self-loops and multiple edges is given. Graph contains n vertices and m edges. For each edge (u, v) f…
E. Minimum spanning tree for each edge time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Connected undirected weighted graph without self-loops and multiple edges is given. Graph contains n …
最小生成树——Minimum Spanning Tree,是图论中比较重要的模型,通常用于解决实际生活中的路径代价最小一类的问题.我们首先用通俗的语言解释它的定义: 对于有n个节点的有权无向连通图,寻找n-1条边,恰好将这n个节点相连,并且这n-1条边的权值之和最小. 对于MST问题,通常常见的解法有两种:Prim算法   或者  Kruskal算法+并查集 对于最小生成树,一定要注意其定义是在无向连通图的基础上,如果在有向图中,那么就需要另外的分析,单纯用无向图中的方法是不能得出正确解的,这一…
time limit per test2 seconds memory limit per test256 megabytes inputstandard input outputstandard output A group of n cities is connected by a network of roads. There is an undirected road between every pair of cities, so there are roads in total. I…
E. Minimum spanning tree for each edge 题目连接: http://www.codeforces.com/contest/609/problem/E Description Connected undirected weighted graph without self-loops and multiple edges is given. Graph contains n vertices and m edges. For each edge (u, v) f…
Problem Description XXX is very interested in algorithm. After learning the Prim algorithm and Kruskal algorithm of minimum spanning tree, XXX finds that there might be multiple solutions. Given an undirected weighted graph with n (1<=n<=100) vertex…
给定一个无向图,如果他的某个子图中,任意两个顶点都能互相连通并且是一棵树,那么这棵树就叫做生成树(spanning tree). 如果边上有权值,那么使得边权和最小的生成树叫做最小生成树(MST,Minimum Spanning Tree).       1.prim版本的算法   .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", co…
time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Connected undirected weighted graph without self-loops and multiple edges is given. Graph contains n vertices and m edges. For each edge (u,…
E. Minimum spanning tree for each edge time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Connected undirected weighted graph without self-loops and multiple edges is given. Graph contains n …
You may refer to the main idea of MST in graph theory. http://en.wikipedia.org/wiki/Minimum_spanning_tree Here is my own interpretation What is Minimum Spanning Tree? Given a connected and undirected graph, a spanning tree of that graph is a subgraph…
Minimum Spanning Tree Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) [Problem Description] XXX is very interested in algorithm. After learning the Prim algorithm and Kruskal algorithm of minimum spanning tree, XXX…
STP生成树协议   问题 为了提高网络的可用性,需要进行冗余和备份.但是冗余路径会产生环路 环路会导致以下问题 广播风暴:由于交换机会对广播.多播.和未知目标MAC的单播包进行泛洪,在存在环路的情况下,很短的时间内就会产生风暴 多帧拷贝.MAC地址表不稳定:当交换机刚刚启动时,MAC地址表是空的,所以,所有的单播帧都会进行泛洪操作.但是如果存在环路的话,交换机在特定情况下,会从不同的接口收到相同的MAC地址,这样的话,MAC地址表将不稳定 STP(spanning tree protocal,…
这题本来是想放在educational round 3的题解里的,但觉得很有意思就单独拿出来写了 题目链接:609E - Minimum spanning tree for each edge 题目大意:n个点,m条边,对每条边,询问包含此边的最小生成树的边权之和 题解:大部分人都是用LCA写的,这里提供一个更为精妙的做法. 模拟Kruskal算法建MST的过程,先将m条边按边权排序,依次进行判断.若点对(u,v)属于同一个连通块,则加入边{u,v,w}后会形成一个环,把环中最大的边换成w会多产…
[BZOJ3080]Minimum Variance Spanning Tree/[BZOJ3754]Tree之最小方差树 题目大意: 给定一个\(n(n\le50)\)个点,\(m(m\le1000)\)条边的带权无向图,每条边的边权为\(w_i(w_i\le50)\).求最小方差生成树. 3080数据范围:\(n\le50,m\le1000,w_i\le50\): 3754数据范围:\(n\le100,m\le1000,w_i\le100\). 其中3754询问的是最小标准差. 思路: 由于…
E. Minimum spanning tree for each edge time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Connected undirected weighted graph without self-loops and multiple edges is given. Graph contains n …
Connected undirected weighted graph without self-loops and multiple edges is given. Graph contains n vertices and m edges. For each edge (u, v) find the minimal possible weight of the spanning tree that contains the edge (u, v). The weight of the spa…
版权声明:本文作者靖心,靖空间地址:http://blog.csdn.net/kenden23/.未经本作者同意不得转载. https://blog.csdn.net/kenden23/article/details/26821635 寻找图中最小连通的路径,图例如以下: 算法步骤: 1. Sort all the edges in non-decreasing order of their weight. 2. Pick the smallest edge. Check if it forms…
Spanning Tree Protocol (STP) in NetScaler Appliance 来源 https://support.citrix.com/article/CTX112341 ------------------------------------------------------------------------------------- Information This contains information about Spanning Tree Protoc…
minimum spanning tree(MST) 最小生成树是连通无向带权图的一个子图,要求 能够连接图中的所有顶点.无环.路径的权重和为所有路径中最小的. graph-cut 对图的一个切割或者叫切断,会使图分离成为两个不相连的顶点集. 它基于树的两个基本属性: 为树的任意两个节点间添加一条边,会在树中形成一个环. 删去树中的一条边,会将原树分离成两棵不相连的树. crossing edge 有了切断的概念,很容易就会问到,被切开的那些边是什么? 切断造成了两个不相连的顶点集,而切断的操作…
Problem Description XXX is very interested in algorithm. After learning the Prim algorithm and Kruskal algorithm of minimum spanning tree, XXX finds that there might be multiple solutions. Given an undirected weighted graph with n (1<=n<=100) vertex…
本节纲要 什么是图(network) 什么是最小生成树 (minimum spanning tree) 最小生成树的算法 什么是图(network)? 这里的图当然不是我们日常说的图片或者地图.通常情况下,我们把图看成是一种由“顶点”和“边”组成的抽象网络.在各个“顶点“间可以由”边“连接起来,使两个顶点间相互关联起来.图的结构可以描述多种复杂的数据对象,应用较为广泛,看下图: 为了更好地说明问题,下面我们看一个比较老套的通信问题: 在各大城市中建设通信网络,如下图所示,每个圆圈代表一座城市,而…
Bichrome Spanning Tree 题意: 给出一个n个点,m条边的无向连通图,现在要给每条边染色,可以染成黑色或者白色. 现在要求在染色完毕后,找出一个至少包含一条黑边和一条白边的最小生成树,使其权值和为X. 问这样的染色方案有多少个? 题解: 题目要求找出一个至少包含一条黑边和白边的最小生成树,那么可能就会存在这种情况:原图的最小生成树所有边都为同色,那这不是我们要求的:我们这时就会去掉一条权值最大的边,再添一条边进来. 那么我们就可以算出包含指定边的最小生成树,方法就是先加我们指…
Red/Blue Spanning Tree Time Limit: 2000ms Memory Limit: 131072KB This problem will be judged on HDU. Original ID: 426364-bit integer IO format: %I64d      Java class name: Main   Given an undirected, unweighted, connected graph, where each edge is co…
前言 说到最小生成树(Minimum Spanning Tree),首先要对以下的图论概念有所了解. 图 图(Graph)是表示物件与物件之间的关系的数学对象,是图论的基本研究对象.图的定义方式有两种,其一是二元组定义.图G是一个有序二元组(V,E),其中V称为顶集(Vertices Set),E称为边集(Edges set),E与V不相交.它们亦可写成V(G)和E(G). 边的方向 边是有方向的,单方向(如只允许从点a到达点b)的边称为单向边或有向边:允许双方互达的边称为双向边或无向边.包含单…
传送门 AND Minimum Spanning Tree Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 131072/131072 K (Java/Others)Total Submission(s): 378    Accepted Submission(s): 190 Problem Description You are given a complete graph with N vertices, numbered fr…
In the mathematical discipline of graph theory, the line graph of a simple undirected weighted graph G is another simple undirected weighted graph L(G) that represents the adjacency between every two edges in G . Precisely speaking, for an undirected…
Problem 1566 - C - Spanning Tree 给出一个联通图,然后每次加一条边,每次需要求最小生成树 1 #include <iostream> 2 #include <cstdio> 3 #include <cstring> 4 #include <cmath> 5 #include <algorithm> 6 #include <string> 7 #include <vector> 8 #incl…