An Improved Algorithm for Online Unit Clustering

  • Authors:
  • Hamid Zarrabi-Zadeh;Timothy M. Chan

  • Affiliations:
  • University of Waterloo, School of Computer Science, Waterloo, Ontario, Canada;University of Waterloo, School of Computer Science, Waterloo, Ontario, Canada

  • Venue:
  • Algorithmica
  • Year:
  • 2009

Quantified Score

Hi-index 0.00

Visualization

Abstract

We revisit the online unit clustering problem in one dimension which we recently introduced at WAOA’06: given a sequence of n points on the line, the objective is to partition the points into a minimum number of subsets, each enclosable by a unit interval. We present a new randomized online algorithm that achieves expected competitive ratio 11/6 against oblivious adversaries, improving the previous ratio of 15/8. This immediately leads to improved upper bounds for the problem in two and higher dimensions as well.