Detect Cycle in a graph

general
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1

Given a directed graph, find whether it contains cycle or not.
Which is the best algorithm for this problem in terms of memory and time complexity? Assuming the graph can contain approx 1 millions nodes.

3 Likes
2

<O(N+M),O(N+M)> a simple DFS will do the job.

3

I think depth first search (stack based) is better to detect a cycle and memory friendly

4

Read this -

 http://www.geeksforgeeks.org/detect-cycle-in-a-graph/
4 Likes
5

Is not what I just said?