Article View: aus.mathematics
Article #59Re: Product and sum of integer array as test for repeats
From: Bruce Varley
Date: Sun, 22 May 2011 10:25
Date: Sun, 22 May 2011 10:25
29 lines
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2776 bytes
<kym@kymhorsell.com> wrote in message news:4dd7cb2e$0$24911$afc38c87@news.optusnet.com.au... > Bruce Varley <bv@nospam.com> wrote: >> This is an outcome of an industrial problem that's been solved with some >> brute force computer work, this posting is just a result of my curiosity. >> We had the task of checking an array of integers for duplicates, due to >> the >> hardware involved the traditional approaches weren't suitable. One of our >> people came up with an algo that works for the cases that we encounter in >> the field, I'm wondering whether the result holds for all n. >> There is an array of n integers between 1 and n, with no repeated >> members, >> in any order. Let P be the product of all the entries, and S be the sum. >> The postulate is that no other set of n integers, all between 1 and n >> (obviously containing repeats) will have the same values for both P and >> S. > > > 1 54 55 sum 110 product 2970 > > 5 6 99 > > --- > You whackos [i.e. "scientists"] just keep changing your "predictions" to > suit reality! > -- BONZO@27-32-240-172 [86 nyms and counting], 16 Feb 2011 15:57 +1100 Yep, the conjecture breaks for n=9 also.
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X-Google-Thread: 10d67e,14bbc351f4d58412 X-Google-NewGroupId: yes X-Google-Attributes: giddfcd5d83b8,domainid0,public,usenet X-Google-Language: ENGLISH,ASCII-7-bit Path: arc1-ca.pugleaf.net!g2news2.google.com!news3.google.com!feeder3.cambriumusenet.nl!feed.tweaknews.nl!217.73.144.44.MISMATCH!ecngs!feeder.ecngs.de!Xl.tags.giganews.com!border1.nntp.ams.giganews.com!nntp.giganews.com!local2.nntp.ams.giganews.com!nntp.westnet.com.au!news.westnet.com.au.POSTED!not-for-mail NNTP-Posting-Date: Sun, 22 May 2011 05:25:29 -0500 From: "Bruce Varley" <bv@NoSpam.com> Newsgroups: aus.mathematics References: <sfednZKGnKXCJkrQnZ2dnUVZ8vSdnZ2d@westnet.com.au> <4dd7cb2e$0$24911$afc38c87@news.optusnet.com.au> Subject: Re: Product and sum of integer array as test for repeats Date: Sun, 22 May 2011 18:25:27 +0800 X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 6.00.2900.5931 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.6090 X-RFC2646: Format=Flowed; Original Message-ID: <UN-dndWEaNQEeUXQnZ2dnUVZ8j6dnZ2d@westnet.com.au> Lines: 31 X-Usenet-Provider: http://www.giganews.com NNTP-Posting-Host: 124.169.160.145 X-Trace: sv3-pLxu89mc+qoDkhCFxOzONZbig0LYfLh146wB2CaLuCUdbVWgTfByDqaCvQQ2gJt0zAVhpNgIzZudfeh!DtohkQ8GixjjIGtKGVTm8M8UzLxmWDnqSY6K5oIXq0cEu5cWJ1F2CIWlLO0zTbc8cpIzDUyY8Y3/!gaWkkjWfT1XcRNCtggCioFk= X-Complaints-To: abuse@westnet.com.au X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.3.40 X-Original-Bytes: 2392