这题可以用次小生成树解,这里用Kruskal算法来做.每条边除维护u,v,w外,还维护: used:表示这条边是否加过 eq:表示有没有与这条边相等的边 del:删除标记,以便删边之用 如果对于一个最小生成树的的边A,有一条与之权值相等的边B,则考虑把A删掉,再求一次最小生成树,看求出的总权值是否与前一个最小生成树的总权值相等.如果相等,则不唯一,如果找遍了这些权值相等的边都没找到,就说明唯一(注意每次不相等的话要把A重新加进来). 代码: #include <iostream> #inclu…

题目:poj 1679 The Unique MST 题意:给你一颗树,让你求最小生成树和次小生成树值是否相等. 分析:这个题目关键在于求解次小生成树. 方法是,依次枚举不在最小生成树上的边,然后加入到最小生成树上,然后把原树上加入了之后形成环的最长的边删去,知道一个最小的.就是次小生成树. 这些须要的都能够在求解最小生成树的时候处理出来. AC代码: #include <cstdio> #include <cstring> #include <iostream> #i…

题目连接 http://poj.org/problem?id=1679 The Unique MST Description Given a connected undirected graph, tell if its minimum spanning tree is unique. Definition 1 (Spanning Tree): Consider a connected, undirected graph G = (V, E). A spanning tree of G is a…

http://poj.org/problem?id=1679 The Unique MST Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 17726   Accepted: 6150 Description Given a connected undirected graph, tell if its minimum spanning tree is unique. Definition 1 (Spanning Tree…

题目链接:http://poj.org/problem?id=1679 The Unique MST Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 29408   Accepted: 10520 Description Given a connected undirected graph, tell if its minimum spanning tree is unique. Definition 1 (Spannin…

The Unique MST 时间限制: 10 Sec  内存限制: 128 MB提交: 25  解决: 10[提交][状态][讨论版] 题目描述 Given a connected undirected graph, tell if its minimum spanning tree is unique. Definition 1 (Spanning Tree): Consider a connected, undirected graph G = (V, E). A spanning tre…

The Unique MST Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 35999   Accepted: 13145 Description Given a connected undirected graph, tell if its minimum spanning tree is unique. Definition 1 (Spanning Tree): Consider a connected, undir…

题目链接:http://poj.org/problem?id=1679 题意: 给你一个图,问你这个图的最小生成树是否唯一. 题解: 求这个图的最小生成树和次小生成树.如果相等,则说明不唯一. 次小生成树(倍增算法): maxn[k][i]:表示从节点i向上走2^k步,这一段中边权的最大值. 枚举每一条不在MST中的边,求出这条边两端点之间在MST上路径上的最大边权mx. 次小生成树(非严格) = max(MST - mx + len) AC Code: #include <iostream>…

The Unique MST Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 22668   Accepted: 8038 Description Given a connected undirected graph, tell if its minimum spanning tree is unique. Definition 1 (Spanning Tree): Consider a connected, undire…

The Unique MST 题目链接: http://acm.hust.edu.cn/vjudge/contest/124434#problem/J Description Given a connected undirected graph, tell if its minimum spanning tree is unique. Definition 1 (Spanning Tree): Consider a connected, undirected graph G = (V, E).…