Exact asymptotics of divide-and-conquer recurrences

Philippe Flajolet, Mordecai Golin

Research output: Chapter in Book/Conference Proceeding/ReportConference Paper published in a bookpeer-review

Abstract

The divide-and-conquer principle is a majol paradigm of algorithms design. Corresponding cost functions satisfy recurrences that directly reflect the decomposition mechanism used in the algorithm. This work shows that periodicity phenomena, often of a fractal nature, are ubiquitous in the performances of these algorithms. Mellin transforms and Dirichlet series are used to attain precise asymptotic estimates. The method is illustrated by a detailed average case, variance and distribution analysis of the classic top-down recursive mergesort algorithm. The approach is applicable to a large number of divide-and-conquer recurrences, and a general theorem is obtained when tile partitioningmerging toll of a divide-and-conquer algorithm is a sublinear function. As another illustration the method is also used to provide an exact analysis of an efficient maxima-finding algorithm.. Exact Asymptotics of Divide-and-Conquer Recurrences Philippe FLAJOLET 1 and Mordecai GOLIN 2 1 Algorithms Project, INRIA Rocquencourt, F-78153 Le Chesnay, France 2 Department of Computer Science, tIKUST, Clear Water Bay, Kowloon, Hong Kong Abstract. The divide-and-conquer principle is a majol paradigm of algorithms design. Corresponding cost functions satisfy recurrences that directly reflect the decomposition mechanism used in the algorithm. This work shows that periodicity phenomena, often of a fractal nature, are ubiquitous in the performances of these algorithms. Mellin transforms and Dirichlet series are used to attain precise asymptotic estimates. The method is illustrated by a detailed average case, variance and distribution analysis of the classic top-down recursive mergesort algorithm. The approach is applicable to a large number of divide-and-conquer recurrences, and a general theorem is obtained when tile partitioningmerging toll of a divide-and-conquer algorithm is a sublinear function. As another illustration the method is also used to provide an exact analysis of an efficient maxima-finding algorithm.

Original languageEnglish
Title of host publicationAutomata, Languages and Programming - 20th International Colloquium, ICALP 1993, Proceedings
EditorsAndrzej Lingas, Rolf Karlsson, Svante Carlsson
PublisherSpringer Verlag
Pages137-149
Number of pages13
ISBN (Print)9783540569398
DOIs
Publication statusPublished - 1993
Event20th International Colloquium on Automata, Languages and Programming, ICALP 1993 - Lund, Sweden
Duration: 5 Jul 19939 Jul 1993

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Volume700 LNCS
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349

Conference

Conference20th International Colloquium on Automata, Languages and Programming, ICALP 1993
Country/TerritorySweden
CityLund
Period5/07/939/07/93

Bibliographical note

Publisher Copyright:
© Springer-Verlag Berlin Heidelberg 1993.

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