Expected time bounds for selection

  • Authors:
  • Robert W. Floyd;Ronald L. Rivest

  • Affiliations:
  • Stanford Univ., Stanford, CA;Stanford Univ., Stanford, CA

  • Venue:
  • Communications of the ACM
  • Year:
  • 1975

Quantified Score

Hi-index 48.31

Visualization

Abstract

A new selection algorithm is presented which is shown to be very efficient on the average, both theoretically and practically. The number of comparisons used to select the ith smallest of n numbers is n + min(i,n-i) + o(n). A lower bound within 9 percent of the above formula is also derived.