The euclidean k-supplier problem

  • Authors:
  • Viswanath Nagarajan;Baruch Schieber;Hadas Shachnai

  • Affiliations:
  • IBM T.J. Watson Research Center, Yorktown Heights, NY;IBM T.J. Watson Research Center, Yorktown Heights, NY;Computer Science Department, Technion, Haifa, Israel

  • Venue:
  • IPCO'13 Proceedings of the 16th international conference on Integer Programming and Combinatorial Optimization
  • Year:
  • 2013

Quantified Score

Hi-index 0.00

Visualization

Abstract

In the k-supplier problem, we are given a set of clients C and set of facilities F located in a metric (C∪F, d), along with a bound k. The goal is to open a subset of k facilities so as to minimize the maximum distance of a client to an open facility, i.e., min S⊆F: |S|=k max v∈Cd(v,S), where d(v,S)= min u∈Sd(v,u) is the minimum distance of client v to any facility in S. We present a $1+\sqrt{3}k-supplier problem in Euclidean metrics. This improves the previously known 3-approximation algorithm [9] which also holds for general metrics (where it is known to be tight). It is NP-hard to approximate Euclidean k-supplier to better than a factor of $\sqrt{7}\approx 2.65$, even in dimension two [5]. Our algorithm is based on a relation to the edge cover problem. We also present a nearly linear O(n·log2n) time algorithm for Euclidean k-supplier in constant dimensions that achieves an approximation ratio of 2.965, where n=|C∪F|.