Algorithms for Satisfiability Using Independent Sets of Variables

  • Ravi Gummadi
  • N. S. Narayanaswamy
  • R. Venkatakrishnan
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 3542)

Abstract

An independent set of variables is one in which no two variables occur in the same clause in a given instance of k-SAT. Instances of k-SAT with an independent set of size i can be solved in time, within a polynomial factor of 2\(^{n-{\it i}}\). In this paper, we present an algorithm for k-SAT based on a modification of the Satisfiability Coding Lemma. Our algorithm runs within a polynomial factor of \(2^{(n-i)(1- \frac{1}{2k-2})}\), where i is the size of an independent set. We also present a variant of Schöning’s randomized local-search algorithm for k-SAT that runs in time which is with in a polynomial factor of \((\frac{2k-3}{k-1})^{n-i}\).

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Copyright information

© Springer-Verlag Berlin Heidelberg 2005

Authors and Affiliations

  • Ravi Gummadi
    • 1
  • N. S. Narayanaswamy
    • 1
  • R. Venkatakrishnan
    • 2
  1. 1.Department of Computer Science and EngineeringIndian Institute of Technology MadrasChennaiIndia
  2. 2.Department of Information TechnologyCrescent Engineering College, VandalurChennaiIndia

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