an:04064509
Zbl 0652.68078
Gibbons, Phillip B.; Miller, Gary L.; Karp, Richard M.; Soroker, Danny
Subtree isomorphism is in random NC
EN
VLSI algorithms and architectures, Proc. 3rd Aegean Workshop Comput., Corfu/Greece 1988, Lect. Notes Comput. Sci. 319, 43-52 (1988).
1988
a
68R10 68Q25 68Q05
subtree isomorphism problem; parallel algorithm; CREW PRAM; Randomization; bipartite perfect matching
[For the entire collection see Zbl 0643.00025.]
Given two trees, a guest tree G and a host tree H, the subtree isomorphism problem is to determine whether there is a subgraph of H that is isomorphic to G. We present a randomized parallel algorithm for finding such an isomorphism, if it exists. The algorithm runs in time \(O(\log^ 3 n)\) on a CREW PRAM, where n is the number of nodes in H. Randomization is used (solely) to solve each of a series of bipartite matching problems during the course of the algorithm. We demonstrate the close connection between the two problems by presenting a log space reduction from bipartite perfect matching to subtree isomorphism. Finally, we present some techniques to reduce the number of processors used by the algorithm.
Zbl 0643.00025