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From: stew@harvard.UUCP
Newsgroups: net.lang
Subject: Re: A Simple Bubble Sort Function
Message-ID: <269@harvard.UUCP>
Date: Wed, 13-Jun-84 23:26:33 EDT
Article-I.D.: harvard.269
Posted: Wed Jun 13 23:26:33 1984
Date-Received: Fri, 22-Jun-84 05:10:02 EDT
References: <965@ihuxq.UUCP> <165@callan.UUCP> <131@godot.UUCP> <2096@mit-eddie.UUCP>, <7471@umcp-cs.UUCP>
Organization: Aiken Computation Lab, Harvard
Lines: 9

Re Torek's assertion that quicksort is O(n^2) for sorting already sorted
lists:  this embarrassing property can be eliminated by sorting a small
sample (say, the first, last, and middle elements) and choosing the
median.  With this change, sorting a sorted list is back to O(log2(n)).
This was originally suggested by Singleton (CACM 12 (1969), 185-187).

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Stew Rubenstein     UUCP: {{ihnp4,allegra}!ima,decvax!genrad!wjh12}!harvard!stew
Harvard Chemistry   ARPA: stew@harvard