Approximating Optimal Bidirectional Macro Schemes
Abstract
Lempel-Ziv is an easy-to-compute member of a wide family of so-called macro schemes; it restricts pointers to go in one direction only. Optimal bidirectional macro schemes are NP-complete to find, but they may provide much better compression on highly repetitive sequences. We consider the problem of approximating optimal bidirectional macro schemes. We describe a simulated annealing algorithm that usually converges quickly. Moreover, in some cases, we obtain bidirectional macro schemes that are provably a 2-approximation of the optimal. We test our algorithm on a number of artificial repetitive texts and verify that it is efficient in practice and outperforms Lempel-Ziv, sometimes by a wide margin.
Cite
@article{arxiv.2003.02336,
title = {Approximating Optimal Bidirectional Macro Schemes},
author = {Luís M. S. Russo and Ana D. Correia and Gonzalo Navarro and Alexandre P. Francisco},
journal= {arXiv preprint arXiv:2003.02336},
year = {2020}
}
Comments
This research has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie Actions H2020-MSCA-RISE-2015 BIRDS GA No. 690941