Path: csiph.com!usenet.pasdenom.info!weretis.net!feeder4.news.weretis.net!feeds.phibee-telecom.net!newsfeed.xs4all.nl!newsfeed2.news.xs4all.nl!xs4all!newsgate.cistron.nl!newsgate.news.xs4all.nl!post.news.xs4all.nl!not-for-mail Return-Path: X-Original-To: python-list@python.org Delivered-To: python-list@mail.python.org X-Spam-Status: OK 0.093 X-Spam-Evidence: '*H*': 0.81; '*S*': 0.00; 'output': 0.05; 'method.': 0.07; 'remaining': 0.07; 'exhaustive': 0.16; 'other,': 0.16; 'potential.': 0.16; 'soap,': 0.16; 'subject:generation': 0.16; 'up*': 0.16; 'elements': 0.16; 'wrote:': 0.18; 'result.': 0.19; 'header:User-Agent:1': 0.23; 'now?': 0.24; 'cheers,': 0.24; 'header:In-Reply-To:1': 0.27; 'generally': 0.29; 'url:mailman': 0.30; 'parameters.': 0.31; 'raised': 0.31; 'probably': 0.32; 'url:python': 0.33; 'url:non-standard http port': 0.33; "i'd": 0.34; 'could': 0.34; 'received:66': 0.35; 'something': 0.35; 'but': 0.35; 'there': 0.35; 'url:listinfo': 0.36; 'doing': 0.36; 'url:org': 0.36; 'list': 0.37; 'to:addr:python-list': 0.38; 'skip:8 10': 0.39; 'to:addr:python.org': 0.39; 'url:mail': 0.40; 'received:unknown': 0.61; 'march': 0.61; 'content- disposition:inline': 0.62; 'header:Message-Id:1': 0.63; 'choose': 0.64; 'more': 0.64; 'skip:\xe2 10': 0.65; 'received:204': 0.75; 'power': 0.76; '100': 0.79; 'age': 0.80; '2015': 0.84; 'boxes': 0.91; 'hundred': 0.95 X-Spam-Status: No, score=0.5 required=5.0 X-Spam-Level: From: Gene Heskett To: python-list@python.org Subject: Re: Speeding up permutations generation Date: Fri, 6 Mar 2015 05:32:03 -0500 User-Agent: KMail/1.9.10 (enterprise35 0.20100827.1168748) References: In-Reply-To: X-KMail-QuotePrefix: > MIME-Version: 1.0 Content-Type: Text/Plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.19 Precedence: list List-Id: General discussion list for the Python programming language List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Newsgroups: comp.lang.python Message-ID: Lines: 35 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1425637934 news.xs4all.nl 2858 [2001:888:2000:d::a6]:43384 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:87012 On Friday 06 March 2015 03:24:48 Abhiram R wrote: > > A list of 100 elements has approximately 9.33 x 10**157 > > permutations. If you could somehow generate one permutation every > > yoctosecond, exhausting them would still take more than a hundred > > orders of magnitude longer than the age of the universe. > > -- > > https://mail.python.org/mailman/listinfo/python-list > > =E2=80=8BTrue that :D I may have exaggerated on the number. Let's consider > something more practically manageable=E2=80=8B =3D> 50 elements with a 50! > permutation. > Is there a solution now? Yes, but its now only 8.881784197e+84 elements so it is still not a=20 practical target. Doing all elements of a matrix is generally equ to=20 n!, and 50 raised to the 50th power is still a number that will probably=20 use up this suns remaining lifetime doing it in assembly. If submitted=20 and accepted to BOINC with its parallelism potential. And=20 Seagate/Western Digital's combined output for about that same time to=20 store the result. I'd choose any other, perhaps less exhaustive method. Or a more=20 practical size of dataset parameters. > =E2=80=8B-Abhiram.R > *~Never give up* Cheers, Gene Heskett =2D-=20 "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." =2DEd Howdershelt (Author) Genes Web page