The isomorphism problem for planar graphs is known to be efficiently solvable. For planar 3-connected graphs, the isomorphism problem can be solved by efficient parallel algorithm...
We make progress in understanding the complexity of the graph reachability problem in the context of unambiguous logarithmic space computation; a restricted form of nondeterminism....
Chris Bourke, Raghunath Tewari, N. V. Vinodchandra...
We show that the reachability problem for directed graphs that are either K3,3-free or K5-free is in unambiguous log-space, UL coUL. This significantly extends the result of Bour...
Reachability and distance computation are known to be NL-complete in general graphs, but within UL co-UL if the graphs are planar. However, finding longest paths is known to be N...