English

A Faster Exact Algorithm to Count X3SAT Solutions

Data Structures and Algorithms 2020-07-16 v1

Abstract

The Exact Satisfiability problem, XSAT, is defined as the problem of finding a satisfying assignment to a formula in CNF such that there is exactly one literal in each clause assigned to be 1 and the other literals in the same clause are set to 0. If we restrict the length of each clause to be at most 3 literals, then it is known as the X3SAT problem. In this paper, we consider the problem of counting the number of satisfying assignments to the X3SAT problem, which is also known as #X3SAT. The current state of the art exact algorithm to solve #X3SAT is given by Dahll\"of, Jonsson and Beigel and runs in O(1.1487n)O(1.1487^n), where nn is the number of variables in the formula. In this paper, we propose an exact algorithm for the #X3SAT problem that runs in O(1.1120n)O(1.1120^n) with very few branching cases to consider, by using a result from Monien and Preis to give us a bisection width for graphs with at most degree 3.

Keywords

Cite

@article{arxiv.2007.07553,
  title  = {A Faster Exact Algorithm to Count X3SAT Solutions},
  author = {Gordon Hoi and Sanjay Jain and Frank Stephan},
  journal= {arXiv preprint arXiv:2007.07553},
  year   = {2020}
}

Comments

Paper accepted at conference CP 2020 which will appear in Springer LNCS proceedings. This is an extended version of that paper which contains additional material. DOI will be added when known

R2 v1 2026-06-23T17:08:00.332Z