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breadth-first search and depth-first search

Two systematic ways to visit every vertex of a graph reachable from a start vertex: BFS fans out level by level, DFS plunges as deep as possible before backing up.

Breadth-first search (BFS) visits vertices in order of increasing distance from the start, using a queue. Depth-first search (DFS) follows one path as far as it can before backtracking, using a stack (or recursion).

See also

BFS shortest paths
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