Faster fixed parameter tractable algorithms for finding feedback vertex sets

  • Authors:
  • Venkatesh Raman;Saket Saurabh;C. R. Subramanian

  • Affiliations:
  • The Institute of Mathematical Sciences, Chennai, India;The Institute of Mathematical Sciences, Chennai, India;The Institute of Mathematical Sciences, Chennai, India

  • Venue:
  • ACM Transactions on Algorithms (TALG)
  • Year:
  • 2006

Quantified Score

Hi-index 0.03

Visualization

Abstract

A feedback vertex set (fvs) of a graph is a set of vertices whose removal results in an acyclic graph. We show that if an undirected graph on n vertices with minimum degree at least 3 has a fvs on at most 1/3n1 − ε vertices, then there is a cycle of length at most 6/ε (for ε ≥ 1/2, we can even improve this to just 6).Using this, we obtain a O((12 log k/log log k + 6)k nω algorithm for testing whether an undirected graph on n vertices has a fvs of size at most k. Here nω is the complexity of the best matrix multiplication algorithm. The previous best parameterized algorithm for this problem took O((2k + 1)kn2) time.We also investigate the fixed parameter complexity of weighted feedback vertex set problem in weighted undirected graphs.