Compact-Table: Efficiently Filtering Table Constraints with Reversible Sparse Bit-Sets
Abstract
In this paper, we describe Compact-Table (CT), a bitwise algorithm to enforce Generalized Arc Consistency (GAC) on table con- straints. Although this algorithm is the default propagator for table constraints in or-tools and OscaR, two publicly available CP solvers, it has never been described so far. Importantly, CT has been recently improved further with the introduction of residues, resetting operations and a data-structure called reversible sparse bit-set, used to maintain tables of supports (following the idea of tabular reduction): tuples are invalidated incrementally on value removals by means of bit-set operations. The experimentation that we have conducted with OscaR shows that CT outperforms state-of-the-art algorithms STR2, STR3, GAC4R, MDD4R and AC5-TC on standard benchmarks.
Cite
@article{arxiv.1604.06641,
title = {Compact-Table: Efficiently Filtering Table Constraints with Reversible Sparse Bit-Sets},
author = {Jordan Demeulenaere and Renaud Hartert and Christophe Lecoutre and Guillaume Perez and Laurent Perron and Jean-Charles Régin and Pierre Schaus},
journal= {arXiv preprint arXiv:1604.06641},
year = {2016}
}