Longest common separable pattern among permutations

  • Authors:
  • Mathilde Bouvel;Dominique Rossin;Stéphane Vialette

  • Affiliations:
  • CNRS, Université Paris Diderot, Paris Cedex 05, France;CNRS, Université Paris Diderot, Paris Cedex 05, France;Laboratoire de Recherche en Informatique, Univ. Paris-Sud XI, Orsay cedex, France

  • Venue:
  • CPM'07 Proceedings of the 18th annual conference on Combinatorial Pattern Matching
  • Year:
  • 2007

Quantified Score

Hi-index 0.00

Visualization

Abstract

In this paper, we study the problem of finding the longest common separable pattern among several permutations. We first give a polynomial-time algorithm when the number of input permutations is fixed and next show that the problem is NP-hard for an arbitrary number of input permutations even if these permutations are separable. On the other hand, we show that the NP-hard problem of finding the longest common pattern between two permutations cannot be approximated better than within a ratio of √opt (where opt is the size of an optimal solution) when taking common patterns belonging to patternavoiding permutation classes.