Algorithms for the edge-width of an embedded graph

  • Authors:
  • Sergio Cabello;íric Colin de Verdière;Francis Lazarus

  • Affiliations:
  • Department of Mathematics, IMFM, Ljubljana, Slovenia and Department of Mathematics, FMF, University of Ljubljana, Slovenia;Laboratoire dinformatique, ícole normale supérieure, CNRS, Paris, France;GIPSA-Lab, CNRS, Grenoble, France

  • Venue:
  • Computational Geometry: Theory and Applications
  • Year:
  • 2012

Quantified Score

Hi-index 0.00

Visualization

Abstract

Let G be an unweighted graph of complexity n embedded in a surface of genus g, orientable or not. We describe improved algorithms to compute a shortest non-contractible and a shortest non-separating cycle in G. If k is an integer, we can compute such a non-trivial cycle with length at most k in O(gnk) time, or correctly report that no such cycle exists. In particular, on a fixed surface, we can test in linear time whether the edge-width or face-width of a graph is bounded from above by a constant. This also implies an output-sensitive algorithm to compute a shortest non-trivial cycle that runs in O(gnk"0) time, where k"0 is the length of the cycle. We also give an approximation algorithm for the shortest non-trivial cycle. If a parameter 0