A Note on (Parallel) Depth- and Breadth-First Search by Arc Elimination

نویسنده

Jesper Larsson Träff

چکیده

This note recapitulates an algorithmic observation for ordered Depth-First Search (DFS) in directed graphs that immediately leads to a parallel algorithm with linear speed-up for a range of processors for non-sparse graphs. The note extends the approach to ordered Breadth-First Search (BFS). With p processors, both DFS and BFS algorithms run in O(m/p + n) time steps on a shared-memory parallel machine allowing concurrent reading of locations, e.g., a CREW PRAM, and have linear speed-up for p ≤ m/n. Both algorithms need n synchronization steps.

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