Exploration  Accepts: 190  Submissions: 976  Time Limit: 30000/15000 MS (Java/Others)  Memory Limit: 131072/131072 K (Java/Others) Problem Description Miceren likes exploration and he found a huge labyrinth underground! This labyrinth has NN caves an…

一.题目链接 http://acm.hdu.edu.cn/showproblem.php?pid=5222 二.题意 给一个无向边+有向边的混合图,其中每条边只能使用一次,问图中是否存在环. 三.思路 1.必备知识点:图中判断是否存在环 图是否连通都没关系. 无向图 (1)DFS (2)BFS (3)并查集 有向图 (1)拓扑排序 无向边+有向边的混合图 (1)法1 ①把所有无向边(u, v)加入到并查集,不加入图中: ②对于所有有向边(u, v),在并查集中找出u和v的根结点x和y,图中添加x…

Treasure Exploration Time Limit: 6000MS   Memory Limit: 65536K Total Submissions: 6558   Accepted: 2644 Description Have you ever read any book about treasure exploration? Have you ever see any film about treasure exploration? Have you ever explored…

RFID Exploration Louis Yi, Mary Ruthven, Kevin O'Toole, & Jay Patterson What did you do? We made an Radio Frequency ID (RFID) card reader and, while attempting to create a long-range spoofer, created an jammer which overcomes card's signals. The read…

Time Limit: 6000MS   Memory Limit: 65536K Total Submissions: 8193   Accepted: 3358 Description Have you ever read any book about treasure exploration? Have you ever see any film about treasure exploration? Have you ever explored treasure? If you neve…

题目传送门 /* 题意:无向图和有向图的混合图判环: 官方题解:首先对于所有的无向边,我们使用并查集将两边的点并起来,若一条边未合并之前, 两端的点已经处于同一个集合了,那么说明必定存在可行的环(因为这两个点处于同一个并查集集合中,那么它们之间至少存在一条路径) 如果上一步没有判断出环,那么仅靠无向边是找不到环的 考虑到,处于同一个并查集集合中的点之间必定存在一条路径互达,因此将一个集合的点合并之后, 原问题等价于在新生成的有向图中是否有环 我们知道,有向无环图必定存在拓扑序,因此只需使用拓扑排…

http://poj.org/problem?id=2594 Treasure Exploration Time Limit: 6000MS   Memory Limit: 65536K Total Submissions: 7398   Accepted: 3025 Description Have you ever read any book about treasure exploration? Have you ever see any film about treasure explo…

  Maze Exploration  A maze of rectangular rooms is represented on a two dimensional grid as illustrated in figure 1a. Each point of the grid is represented by a character. The points of room walls are marked by the same character which can be any pri…

Treasure Exploration Time Limit: 6000MS   Memory Limit: 65536K Total Submissions: 7455   Accepted: 3053 Description Have you ever read any book about treasure exploration? Have you ever see any film about treasure exploration? Have you ever explored…

POJ 2594 Treasure Exploration 题目链接 题意:有向无环图,求最少多少条路径能够覆盖整个图,点能够反复走 思路:和普通的最小路径覆盖不同的是,点能够反复走,那么事实上仅仅要在多一步.利用floyd求出传递闭包.然后依据这个新的图去做最小路径覆盖就可以 代码: #include <cstdio> #include <cstring> #include <vector> #include <algorithm> using names…