On multiway cut parameterized above lower bounds

  • Authors:
  • Marek Cygan;Marcin Pilipczuk;Michał Pilipczuk;Jakub Onufry Wojtaszczyk

  • Affiliations:
  • University of Warsaw, Poland;University of Warsaw, Poland;University of Warsaw, Poland;Google Inc., Warsaw, Poland

  • Venue:
  • ACM Transactions on Computation Theory (TOCT)
  • Year:
  • 2013

Quantified Score

Hi-index 0.00

Visualization

Abstract

We introduce a concept of parameterizing a problem above the optimum solution of its natural linear programming relaxation and prove that the node multiway cut problem is fixed-parameter tractable (FPT) in this setting. As a consequence we prove that node multiway cut is FPT, when parameterized above the maximum separating cut, resolving an open problem of Razgon. Our results imply O*(4k) algorithms for vertex cover above maximum matching and almost 2-SAT as well as an O*(2k) algorithm for node multiway cut with a standard parameterization by the solution size, improving previous bounds for these problems.