Choose BFS over DFS when

Question

Accepted Answer

C. you need the shortest hop count from a source to other vertices

BFS reaches vertices by increasing edge distance, so it naturally gives shortest hop counts in unweighted graphs.
Cycle detection and timestamps are DFS specialities (back edges flag cycles, discovery/finish times power topological sort and SCC).
Trees can use either
the choice depends on the question, not the graph type.

Answer

the graph is a tree, not a general graph

Answer

you need cycle detection in a directed graph

Answer

you want to compute discovery and finish timestamps

Choose BFS over DFS when

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