Locally consistent constraint satisfaction problems

  • Authors:
  • Zdeněk Dvořák;Daniel Král;Ondřej Pangrác

  • Affiliations:
  • Department of Applied Mathematics and Institute for Theoretical Computer Science, Faculty of Mathematics and Physics, Charles University, Prague, Czech Republic;Department of Applied Mathematics and Institute for Theoretical Computer Science, Faculty of Mathematics and Physics, Charles University, Prague, Czech Republic and Institute for Mathematics, Tech ...;Department of Applied Mathematics and Institute for Theoretical Computer Science, Faculty of Mathematics and Physics, Charles University, Prague, Czech Republic

  • Venue:
  • Theoretical Computer Science - Automata, languages and programming: Algorithms and complexity (ICALP-A 2004)
  • Year:
  • 2005

Quantified Score

Hi-index 0.00

Visualization

Abstract

An instance of a constraint satisfaction problem is l-consistent if any l constraints of it can be simultaneously satisfied. For a set Π of constraint types ρl (Π) denotes the largest ratio of constraints which can be satisfied in any l-consistent instance composed by constraints of types from Π. In the case of sets Π consisting of finitely many Boolean predicates, we express the limit ρ∞ (Π) : =liml→∞ ρl(Π) as the minimum of a certain functional on a convex set of polynomials. Our results yield a robust deterministic algorithm (for a fixed set Π) running in time linear in the size of the input and 1/ε which finds either an inconsistent set of constraints (of size bounded by the function of ε) or a truth assignment which satisfies the fraction of at least ρ∞ (Π) - ε of the given constraints. We also compute the values of ρl ({P}) for several specific predicates P.