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Hoare's Selection Algorithm: A Markov Chain Approach

Published online by Cambridge University Press:  14 July 2016

Rudolf Grübel*
Affiliation:
Universität Hannover
*
Postal address: Institut für Mathematische Stochastik, Universität Hannover, Postfach 60 09, D-30060 Hannover, Germany. e-mail address: rgrubel@stochastik.uni-hannover.de

Abstract

We obtain bounds for the distribution of the number of comparisons needed by Hoare's randomized selection algorithm FIND and give a new proof for Grübel and Rösler's (1996) result on the convergence of this distribution. Our approach is based on the construction and analysis of a suitable associated Markov chain. Some numerical results for the quantiles of the limit distributions are included, leading for example to the statement that, for a set S with n elements and n large, FIND will need with probability 0.9 about 4.72 x n comparisons to find the median of S.

Type
Research Papers
Copyright
Copyright © Applied Probability Trust 1998 

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References

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