PTAS for k-Tour Cover Problem on the Plane for Moderately Large Values of k

  • Authors:
  • Anna Adamaszek;Artur Czumaj;Andrzej Lingas

  • Affiliations:
  • Centre for Discrete Mathematics and its Applications (DIMAP) and Department of Computer Science, University of Warwick, UK;Centre for Discrete Mathematics and its Applications (DIMAP) and Department of Computer Science, University of Warwick, UK;Department of Computer Science, Lund University, Lund, Sweden 22100

  • Venue:
  • ISAAC '09 Proceedings of the 20th International Symposium on Algorithms and Computation
  • Year:
  • 2009

Quantified Score

Hi-index 0.00

Visualization

Abstract

Let P be a set of n points in the Euclidean plane and let O be the origin point in the plane. In the k-tour cover problem (called frequently the capacitated vehicle routing problem), the goal is to minimize the total length of tours that cover all points in P, such that each tour starts and ends in O and covers at most k points from P.The k-tour cover problem is known to be $\mathcal{NP}$-hard. It is also known to admit constant factor approximation algorithms for all values of k and even a polynomial-time approximation scheme (PTAS) for small values of k, $k=\O(\log n / \log\log n)$.In this paper, we significantly enlarge the set of values of k for which a PTAS is provable. We present a new PTAS for all values of $k \le 2^{\log^{\delta}n}$, where 驴 = 驴(驴). The main technical result proved in the paper is a novel reduction of the k-tour cover problem with a set of n points to a small set of instances of the problem, each with $\O((k/\epsilon)^{\O(1)})$ points.