题目链接:Click here 题目大意:两个点之间的边权为编号按位与的值,求最小生成树,方案要字典序最小 Solution: 一道不难的构造题,每个点连向他取反后的lowbit值,这样边权为0,若lowbit值大于n,则连1 这样自构造出来的必然是最小生成树,且满足字典序最小 Code: #include<bits/stdc++.h> using namespace std; const int N=2e5+1; int n,ans=0,a[N]; int lowbit(int x){ret…

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…

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…

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 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 …

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…

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…

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…