geeks上的解答复杂了些,用回溯就行了 #include <iostream> #include <vector> #include <algorithm> #include <queue> #include <stack> #include <string> #include <fstream> using namespace std; ; vector<int> trace; vector<bool…

Detect Cycle in a Directed Graph 推断一个图是否有环,有环图例如以下: 这里唯一注意的就是,这是个有向图, 边组成一个环,不一定成环,由于方向能够不一致. 这里就是添加一个数组保存当前已经訪问过的路径信息 recStack[]: 而visited[]数组是訪问过的点的信息,两者作用是不一样的. 知道这个知识点,这道题就非常easy了. 原文: http://www.geeksforgeeks.org/detect-cycle-in-a-graph/ #includ…

Question: Detect cycle in a directed graph Answer: Depth First Traversal can be used to detect cycle in a Graph. DFS for a connected graph produces a tree. There is a cycle in a graph only if there is a back edge present in the graph. A back edge is…

A graph is a data structure comprised of a set of nodes, also known as vertices, and a set of edges. Each node in a graph may point to any other node in the graph. This is very useful for things like describing networks, creating related nonhierarchi…

如果为undirected graph就是dfs或者bfs,如果都能visit则为连通O(V+E). 如果为directed graph就先dfs或者bfs,再reverse direct,再dfs或者bfs,如果两次都连通则为strong connect http://www.geeksforgeeks.org/connectivity-in-a-directed-graph/…

Given a Directed Graph and two vertices in it, check whether there is a path from the first given vertex to second. For example, in the following graph, there is a path from vertex 1 to 3. As another example, there is no path from 3 to 0. We can eith…

Counting on a directed graph Problem Code: GRAPHCNT All submissions for this problem are available. Read problems statements in Mandarin Chineseand Russian. Given an directed graph with N nodes (numbered from 1 to N) and M edges, calculate the number…

4.2 Given a directed graph, design an algorithm to find out whether there is a route between two nodes. LeetCode和CareerCup中关于图的题都不是很多,LeetCode中只有三道,分别是Clone Graph 无向图的复制,Course Schedule 课程清单 和 Course Schedule II 课程清单之二.目前看来CareerCup中有关图的题在第四章中仅此一道,这是…

  Find the number Weak Connected Component in the directed graph. Each node in the graph contains a label and a list of its neighbors. (a connected set of a directed graph is a subgraph in which any two vertices are connected by direct edge path.) Ex…

这里总结针对一个并不一定所有点都连通的general directed graph, 去判断graph里面是否有loop存在, 收到启发是因为做了[LeetCode] 207 Course Schedule_Medium tag: BFS, DFS, 这个题实际上就是监测directed graph里面是否有loop存在. 我在网上看了比较经典的做法为DFS, 并且用三个set去标志not visited点,(0), 正在visiting的点(-1), 已经visited过的点(1), 我结合这…