Adaptive intersection and t-threshold problems

  • Authors:
  • Jérémy Barbay;Claire Kenyon

  • Affiliations:
  • Université Paris-Sud, 91405 ORSAY Cedex, FRANCE;Université Paris-Sud, 91405 ORSAY Cedex, FRANCE

  • Venue:
  • SODA '02 Proceedings of the thirteenth annual ACM-SIAM symposium on Discrete algorithms
  • Year:
  • 2002

Quantified Score

Hi-index 0.00

Visualization

Abstract

Consider the problem of computing the intersection of k sorted sets. In the comparison model, we prove a new lower bound which depends on the non-deterministic complexity of the instance, and implies that the algorithm of Demaine, López-Ortiz and Munro [2] is usually optimal in this "adaptive" sense. We extend the lower bound and the algorithm to the t-Threshold Problem, which consists in finding the elements which are in at least t of the k sets. These problems are motivated by boolean queries in text database systems.