Lower bounds for external algebraic decision trees

  • Authors:
  • Jeff Erickson

  • Affiliations:
  • University of Illinois at Urbana-Champaign

  • Venue:
  • SODA '05 Proceedings of the sixteenth annual ACM-SIAM symposium on Discrete algorithms
  • Year:
  • 2005

Quantified Score

Hi-index 0.01

Visualization

Abstract

We propose a natural extension of algebraic decision trees to the external-memory setting, where the cost of disk operations overwhelms CPU time, and prove a tight lower bound of Ω(n logm n) on the complexity of both sorting and element uniqueness in this model of computation. We also prove a Ω(min{n logm n, N}) lower bound for both problems in a less restrictive model, which requires only that the worst-case internal-memory computation time is finite. Standard reductions immediately generalize these lower bounds to a large number of fundamental computational geometry problems.