An improved approximation algorithm for TSP with distances one and two

  • Authors:
  • M. Bläser;L. Shankar Ram

  • Affiliations:
  • Institut für Theoretische Informatik, ETH Zürich, Zürich, Switzerland;Institut für Theoretische Informatik, ETH Zürich, Zürich, Switzerland

  • Venue:
  • FCT'05 Proceedings of the 15th international conference on Fundamentals of Computation Theory
  • Year:
  • 2005

Quantified Score

Hi-index 0.00

Visualization

Abstract

The minimum traveling salesman problem with distances one and two is the following problem: Given a complete undirected graph G=(V,E) with a cost function w: E→ {1, 2}, find a Hamiltonian tour of minimum cost. In this paper, we provide an approximation algorithm for this problem achieving a performance guarantee of $\frac{315}{271}$. This algorithm can be further improved obtaining a performance guarantee of $\frac{65}{56}$. This is better than the one achieved by Papadimitriou and Yannakakis [8], with a ratio $\frac{7}{6}$, more than a decade ago. We enhance their algorithm by an involved procedure and find an improved lower bound for the cost of an optimal Hamiltonian tour.