The paper is devoted to lower bounds on the time complexity of DPLL algorithms that solve the satisfiability problem using a splitting strategy. Exponential lower bounds on the running time of DPLL algorithms on unsatisfiable formulas follow from the lower bounds for resolution proofs. Lower bounds on satisfiable instances are also known for some classes of DPLL algorithms; this lower bounds are usually based on reductions to unsatisfiable instances. In this paper we consider DPLL algorithms with a cut heuristic that may decide that some branch of the splitting tree will not be investigated. DPLL algorithms with a cut heuristic always return correct answer on unsatisfiable formulas while they may err on satisfiable instances. We prove the theorem about effectiveness vs. correctness trade-off for deterministic myopic DPLL algorithms with cut heuristic. Myopic algorithms can see formulas with erased signs of negations; they may also request a small number of clauses to read them precisely. We construct a family of unsatisfiable formulas Φ (n) and a polynomial time samplable ensemble of distributions Q n concentrated on satisfiable formulas such that every deterministic myopic algorithm that gives a correct answer with probability 1-o(1) on a random formula from the ensemble Q n runs exponential time on the formulas Φ (n).

Original languageEnglish
Title of host publicationAlgorithms and Computation - 22nd International Symposium, ISAAC 2011, Proceedings
Pages464-473
Number of pages10
DOIs
StatePublished - 26 Dec 2011
Event22nd International Symposium on Algorithms and Computation, ISAAC 2011 - Yokohama, Japan
Duration: 5 Dec 20118 Dec 2011

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Volume7074 LNCS
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349

Conference

Conference22nd International Symposium on Algorithms and Computation, ISAAC 2011
Country/TerritoryJapan
CityYokohama
Period5/12/118/12/11

    Scopus subject areas

  • Theoretical Computer Science
  • Computer Science(all)

ID: 49786553