1.25-Approximation Algorithm for Steiner Tree Problem with Distances 1 and 2

  • Piotr Berman
  • Marek Karpinski
  • Alexander Zelikovsky
Part of the Lecture Notes in Computer Science book series (LNCS, volume 5664)

Abstract

Given a connected graph G = (V,E) with nonnegative costs on edges, \(c:E\rightarrow {\mathcal R}^+\), and a subset of terminal nodes R ⊂ V, the Steiner tree problem asks for the minimum cost subgraph of G spanning R. The Steiner Tree Problem with distances 1 and 2 (i.e., when the cost of any edge is either 1 or 2) has been investigated for long time since it is MAX SNP-hard and admits better approximations than the general problem. We give a 1.25 approximation algorithm for the Steiner Tree Problem with distances 1 and 2, improving on the previously best known ratio of 1.279.

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Copyright information

© Springer-Verlag Berlin Heidelberg 2009

Authors and Affiliations

  • Piotr Berman
    • 1
  • Marek Karpinski
    • 2
  • Alexander Zelikovsky
    • 3
  1. 1.Department of Computer Science & EngineeringPennsylvania State UniversityUSA
  2. 2.Department of Computer ScienceUniversity of BonnBonnGermany
  3. 3.Department of Computer ScienceGeorgia State UniversityAtlantaUSA

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