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Groups > comp.lang.java.programmer > #10503

Re: Verifying a list is alphabetized

From Martin Gregorie <martin@address-in-sig.invalid>
Newsgroups comp.lang.java.programmer
Subject Re: Verifying a list is alphabetized
Date 2011-12-04 23:41 +0000
Organization UK Free Software Network
Message-ID <jbh0ft$a0$1@localhost.localdomain> (permalink)
References (2 earlier) <4ed9732b$0$294$14726298@news.sunsite.dk> <jbd5k5$86c$1@dont-email.me> <b5sld7ltif6oi2tke3q2fkr5vnr2cc6nkc@4ax.com> <jbfpru$ksi$2@localhost.localdomain> <alpine.DEB.2.00.1112042147290.3416@urchin.earth.li>

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On Sun, 04 Dec 2011 22:11:32 +0000, Tom Anderson wrote:

> Tony Hoare, being a scholar and a gentleman, made a strong but measured
> claim about it (from the conclusion of [1]):
>
This was in "Software Tools in Pascal" (Kernighan & Plauger).
 
> I very much doubt that anyone worth listening to has ever made a claim
> that quicksort is the fastest in every situation. Pathological cases
> have been known for such a long time that to do so would be to court
> honorary membership of the Flat Earth Society.
>
K&P describe shellsort as approximating N**1.5 and say that it averages 
NlogN but can degrade to n**2 but that worse than NlogN is 'very rare', 
addinf that to sort an array "just enter 'quick(v, 1, n)' and stand well 
back". I probably ascribed too much weight to that remark, but OTOH the 
book says almost nothing about what can degrade its performance.

It then goes on to talk about sort-merges which I really related to since 
I was using a box with 48K RAM at the time and wasn't long away from 
mainframes with little RAM (multi-user operation with 32 Kwords of RAM: 
96 KB equivalent), so all disk sort utilities were of the sort-merge 
variety - tape sorts were pure multi-way merges preceeded by a collation 
phase).


-- 
martin@   | Martin Gregorie
gregorie. | Essex, UK
org       |

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Thread

Verifying a list is alphabetized laredotornado <laredotornado@zipmail.com> - 2011-11-30 07:52 -0800
  Re: Verifying a list is alphabetized Knute Johnson <nospam@knutejohnson.com> - 2011-11-30 08:05 -0800
    Re: Verifying a list is alphabetized Lew <lewbloch@gmail.com> - 2011-11-30 11:18 -0800
    Re: Verifying a list is alphabetized Arne Vajhøj <arne@vajhoej.dk> - 2011-12-02 19:54 -0500
      Re: Verifying a list is alphabetized Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-12-03 07:44 -0500
        Re: Verifying a list is alphabetized Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-12-03 09:02 -0500
        Re: Verifying a list is alphabetized Roedy Green <see_website@mindprod.com.invalid> - 2011-12-03 20:05 -0800
          Re: Verifying a list is alphabetized Roedy Green <see_website@mindprod.com.invalid> - 2011-12-03 22:13 -0800
            Re: Verifying a list is alphabetized Tom Anderson <twic@urchin.earth.li> - 2011-12-04 21:47 +0000
          Re: Verifying a list is alphabetized Martin Gregorie <martin@address-in-sig.invalid> - 2011-12-04 12:42 +0000
            Re: Verifying a list is alphabetized Patricia Shanahan <pats@acm.org> - 2011-12-04 12:18 -0800
              Re: Verifying a list is alphabetized Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2011-12-04 13:17 -0800
                Re: Verifying a list is alphabetized Patricia Shanahan <pats@acm.org> - 2011-12-04 15:32 -0800
                Re: Verifying a list is alphabetized markspace <-@.> - 2011-12-04 15:59 -0800
                Re: Verifying a list is alphabetized Patricia Shanahan <pats@acm.org> - 2011-12-04 16:14 -0800
                Re: Verifying a list is alphabetized markspace <-@.> - 2011-12-04 17:12 -0800
                Re: Verifying a list is alphabetized Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-12-04 21:17 -0500
            Re: Verifying a list is alphabetized Tom Anderson <twic@urchin.earth.li> - 2011-12-04 22:11 +0000
              Re: Verifying a list is alphabetized Martin Gregorie <martin@address-in-sig.invalid> - 2011-12-04 23:41 +0000
              Re: Verifying a list is alphabetized Roedy Green <see_website@mindprod.com.invalid> - 2011-12-12 01:39 -0800
          Re: Verifying a list is alphabetized Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-12-04 08:47 -0500
          Re: Verifying a list is alphabetized Gene Wirchenko <genew@ocis.net> - 2011-12-04 21:34 -0800
  Re: Verifying a list is alphabetized Patricia Shanahan <pats@acm.org> - 2011-11-30 12:52 -0800
    Re: Verifying a list is alphabetized laredotornado <laredotornado@zipmail.com> - 2011-12-01 06:43 -0800
  Re: Verifying a list is alphabetized Joshua Maurice <joshuamaurice@gmail.com> - 2011-11-30 13:16 -0800
  Re: Verifying a list is alphabetized Roedy Green <see_website@mindprod.com.invalid> - 2011-12-02 01:43 -0800
    Re: Verifying a list is alphabetized Patricia Shanahan <pats@acm.org> - 2011-12-02 05:58 -0800
      Re: Verifying a list is alphabetized Arne Vajhøj <arne@vajhoej.dk> - 2011-12-02 19:55 -0500
      Re: Verifying a list is alphabetized Roedy Green <see_website@mindprod.com.invalid> - 2011-12-03 02:54 -0800
        Re: Verifying a list is alphabetized Patricia Shanahan <pats@acm.org> - 2011-12-03 06:17 -0800
    Re: Verifying a list is alphabetized Roedy Green <see_website@mindprod.com.invalid> - 2011-12-03 03:10 -0800
  Re: Verifying a list is alphabetized Arne Vajhøj <arne@vajhoej.dk> - 2011-12-02 19:52 -0500

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