Approximating the maximum 3- and 4-edge-colorable subgraph

  • Authors:
  • Marcin Kamiński;Łukasz Kowalik

  • Affiliations:
  • Département d'Informatique, Université Libre de Bruxelles;Institute of Informatics, University of Warsaw

  • Venue:
  • SWAT'10 Proceedings of the 12th Scandinavian conference on Algorithm Theory
  • Year:
  • 2010

Quantified Score

Hi-index 0.00

Visualization

Abstract

We study large k-edge-colorable subgraphs of simple graphs and multigraphs. We show that: every simple subcubic graph G has a 3-edge-colorable subgraph (3-ECS) with at least $\frac{13}{15}|E(G)|$ edges, unless G is isomorphic to K4 with one edge subdivided, every subcubic multigraph G has a 3-ECS with at least $\frac{7}{9}|E(G)|$ edges, unless G is isomorphic to K3 with one edge doubled, every simple graph G of maximum degree 4 has a 4-ECS with at least $\frac{5}{6}|E(G)|$ edges, unless G is isomorphic to K5. We use these combinatorial results to design new approximation algorithms for the Maximum k-Edge-Colorable Subgraph problem. In particular, for k=3 we obtain a $\frac{13}{15}$-approximation for simple graphs and a $\frac{7}{9}$-approximation for multigraphs; and for k=4, we obtain a $\frac{9}{11}$-approximation. We achieve this by presenting a general framework of approximation algorithms that can be used for any value of k.