Is Depth-First Search Order for Graph Traversal Direction-Agnostic?

[gfd43tg]

Hello, I drew up this graph to try and understand the concept of depth-first search. Starting at node C, I was wondering if its correct for the order to be C-A-B-D or C-B-A-D? It seems like you can traverse in either direction without a problem.

 

[verty]

For me, both are valid. You could certainly look at all the children, order them by some preference and visit each one in that order.

 

[gfd43tg]

I'm confused as to what movements are not allowed? It seems very unclear to me what is a legitimate traversal and what isn't. Can you go C-D-B-A or C-D-A-B? What counts as not being permitted?

 

[verty]

Depth-first means the whole subtree of each child node is processed before any other child nodes are processed. Does that make sense? Your example tree is a bad example because the children of C have no children themselves.

Oh sorry, you are talking about a graph, not a tree. Hmm.

 

[verty]

Ok, for a graph, depth-first must mean, process every unvisited neighbor before backtracking. CAD -- not allowed.