Parameterized complexity of the smallest degree-constrained subgraph problem

  • Authors:
  • Omid Amini;Ignasi Sau;Saket Saurabh

  • Affiliations:
  • Max-Planck-Institut für Informatik;INRIA, CNRS, I3S, UNSA, Sophia-Antipolis, France and Graph Theory and Combinatorics group, Applied Mathematics IV, Department of UPC, Barcelona, Spain;Department of Informatics, University of Bergen, Bergen, Norway

  • Venue:
  • IWPEC'08 Proceedings of the 3rd international conference on Parameterized and exact computation
  • Year:
  • 2008

Quantified Score

Hi-index 0.00

Visualization

Abstract

In this paper we study the problem of finding an induced subgraphof size at most k with minimum degree at least d for a given graphG, from the parameterized complexity perspective. We call this problemMinimum Subgraph of Minimum Degree ≥d (MSMDd). For d = 2 itcorresponds to finding a shortest cycle of the graph. Our main motivationto study this problem is its strong relation to Dense k-Subgraphand Traffic Grooming problems. First, we show that MSMSd is fixed-parameter intractable (providedFPT ≠ W[1]) for d ≥ 3 in general graphs, by showing it to be W[1]-hardusing a reduction from Multi-Color Clique. In the second part of thepaper we provide explicit fixed-parameter tractable (FPT) algorithmsfor the problem in graphs with bounded local tree-width and graphswith excluded minors, faster than those coming from the meta-theorem of Frick and Grohe [13] about problems definable in first order logicover "locally tree-decomposable structures". In particular, this impliesfaster fixed-parameter tractable algorithms in planar graphs, graphs ofbounded genus, and graphs with bounded maximum degree.