Optimal parallel selection has complexity O(Log Log N)

Miklós Ajtai, János Komlós, W. L. Steiger, Endre Szemerédi

Research output: Contribution to journalArticle

23 Citations (Scopus)


We show that in the deterministic comparison model for parallel computation, p = n processors can select the kth smallest item from a set of n numbers in O(log log n) parallel time. With this result all comparison tasks (selection, merging, sorting) now have upper and lower bounds of the same order in both random and deterministic models. This optimal time bound holds even if p = o(n).

Original languageEnglish
Pages (from-to)125-133
Number of pages9
JournalJournal of Computer and System Sciences
Issue number1
Publication statusPublished - Feb 1989


ASJC Scopus subject areas

  • Theoretical Computer Science
  • Computer Networks and Communications
  • Computational Theory and Mathematics
  • Applied Mathematics

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