ALCOMFT-TR-01-102

Daniele Frigioni, Tobias Miller, Umberto Nanni and Christos Zaroliagis
An Experimental Study of Dynamic Algorithms for Transitive Closure
Patras and Rome. Work package 5. May 2001.

Abstract: We perform an extensive experimental study of several dynamic algorithms for transitive closure. In particular, we implemented algorithms given by Italiano, Yellin, Cicerone et al., and two recent randomized algorithms by Henzinger and King. We propose a fine-tuned version of Italiano's algorithms as well as a new variant of them, both of which were always faster than any of the other implementations of the dynamic algorithms. We also considered simple-minded algorithms that were easy to implement and likely to be fast in practice. We tested and compared the above implementations on random inputs, on non-random inputs that are worst-case inputs for the dynamic algorithms, and on an input motivated by a real-world graph.

Postscript file: ALCOMFT-TR-01-102.ps.gz (195 kb).