Linear-time in-place selection in less than 3n comparisons
1995 (English)In: Proceedings of the 6th International Symposium on Algorithms and Computation: ISAAC'95 / [ed] John Staples, Berlin: Encyclopedia of Global Archaeology/Springer Verlag, 1995, 244-253 p.Conference paper (Refereed)
By developing and exploiting new in-place techniques, we show that finding the element with the median value out of n elements stored in an array can be performed in-place in (2.95 + e)n (for any c > 0) comparisons and in linear time. This is arbitrarily close to the upper bound for the same problem without space-restrictions. To make the algorithm competitive we also try to minimize the number of element moves performed by the algorithm since this is the other critical operation. This has resulted in a trade-off between the number of comparisons and the number of moves. By minimizing the sum of the critical operations we achieve an algorithm that uses at most 3.75n comparisons and 9n moves for finding the median in-place. This is, in principle, twice as good as earlier attempts on implicit selection for both of the operations.
Place, publisher, year, edition, pages
Berlin: Encyclopedia of Global Archaeology/Springer Verlag, 1995. 244-253 p.
Lecture Notes in Computer Science, ISSN 0302-9743 ; 1004
Research subject Dependable Communication and Computation Systems
IdentifiersURN: urn:nbn:se:ltu:diva-34687DOI: 10.1007/BFb0015429Local ID: 8f465c70-a287-11dc-ac39-000ea68e967bISBN: 3-540-60573-8OAI: oai:DiVA.org:ltu-34687DiVA: diva2:1007938
International Symposium on Algorithms and Computation : 04/12/1995 - 06/12/1995
Godkänd; 1995; 20071204 (ysko)2016-09-302016-09-30Bibliographically approved