Directed or Undirected Depth-first Search (DFS)
Category: Network Flows
Input
A graph $G = (V, E)$ and a vertex $s$.
Problem
Construct the depth-first search numbering of $G$ starting from vertex $s$.
Status
Open (Aggarwal and Anderson [1], Aggarwal, Anderson, and Kao [2]).
Remarks
$\mathsf{RNC}$ algorithms are now known for both the undirected [1] and directed [2] cases, subsuming earlier $\mathsf{RNC}$ results for planar graphs (Smith [3]). For directed acyclic graphs, DFS is in $\NC$ (de la Torre and Kruskal [4][5], Greenlaw [6]).
References
- A. Aggarwal and R. J. Anderson (1988). A Random NC algorithm for depth first search.
- A. Aggarwal, R. J. Anderson, and M.-Y. Kao (1990). Parallel depth-first search in general directed graphs.
- J. R. Smith (1986). Parallel algorithms for depth first searches I: Planar graphs.
- P. de la Torre and C. P. Kruskal (1989). Fast parallel algorithms for all sources lexicographic search and path finding problems.
- P. de la Torre and C. P. Kruskal (1991). Fast and efficient parallel algorithms for single source lexicographic depth-first search, breadth-first search and topological-first search.
- R. Greenlaw (1992). A model classifying algorithms as inherently sequential with applications to graph searching.
- Greenlaw, R., Hoover, H. J., and Ruzzo, W. L. (1995). Limits to Parallel Computation: P-Completeness Theory. Oxford University Press. Problem B.9.2.