Question

In DFS, how many times is a node visited?

I'm a bit confused about how many times a node is visited in DFS. I thought each node might be visited multiple times if there are cycles in the graph, but I’ve also read that DFS should only visit each node once

Answer 1

In Depth-First Search (DFS), each node is visited once when it is initially discovered. Once DFS visits a node, it marks it as visited, so it does not revisit the node in the same DFS traversal.

However, depending on the implementation, a node may be encountered multiple times when revisiting neighbors, but it’s only processed once.