The complexity of two graph orientation problems

  • Authors:
  • Nicole Eggemann;Steven D. Noble

  • Affiliations:
  • -;-

  • Venue:
  • Discrete Applied Mathematics
  • Year:
  • 2012

Quantified Score

Hi-index 0.04

Visualization

Abstract

We consider two orientation problems in a graph, namely the minimization of the sum of all the shortest path lengths and the minimization of the diameter. Our main result is that for each positive integer k, there is a linear-time algorithm that decides for a planar graph Gwhether there is an orientation for which the diameter is at most k. We also extend this result from planar graphs to any minor-closed family F not containing all apex graphs. In contrast, it is known to be NP-complete to decide whether a graph has an orientation such that the sum of all the shortest path lengths is at most an integer specified in the input. We give a simpler proof of this result.