Re: Euler 13

From	Paul Rubin <no.email@nospam.invalid>
Newsgroups	comp.lang.forth
Subject	Re: Euler 13
Date	2013-05-26 21:25 -0700
Organization	Nightsong/Fort GNOX
Message-ID	<7xvc65ujzq.fsf@ruckus.brouhaha.com> (permalink)
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albert@spenarnc.xs4all.nl (Albert van der Horst) writes:
> To appreciate what nowadays is a trivial problem look at 429,
> the first solution within 1 minute, and I pasted a solution
> together from 3 existing Forth fragments.

I haven't figured out the trick for this yet.  The obvious brute force
algorithm and various optimizations of it are completely impractical.
1e8! has over 5 million distinct prime factors, and you have to sum the
products over all the subsets of them.  I can sort of smell some algebra
that might help, but haven't yet put my finger on it.  Typically writing
the code of these problems is easy after you figure out the trick.  But
I'd say figuring out the trick for this one isn't so trivial.  (Of
course it becomes trivial once figured out).

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comp.lang.forth.applications johno <email@address.com> - 2013-05-23 15:35 +0100
  Re: comp.lang.forth.applications albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-05-23 15:38 +0000
    Re: comp.lang.forth.applications "Elizabeth D. Rather" <erather@forth.com> - 2013-05-23 08:25 -1000
      Re: comp.lang.forth.applications Mentifex <mentifex@myuw.net> - 2013-05-23 11:43 -0700
    Re: comp.lang.forth.applications visualforth@rocketmail.com - 2013-05-23 18:35 -0700
      Re: comp.lang.forth.applications Paul Rubin <no.email@nospam.invalid> - 2013-05-23 22:38 -0700
        Re: comp.lang.forth.applications albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-05-24 08:52 +0000
          Re: comp.lang.forth.applications visualforth@rocketmail.com - 2013-05-25 17:52 -0700
            Re: comp.lang.forth.applications Paul Rubin <no.email@nospam.invalid> - 2013-05-25 18:18 -0700
        Re: comp.lang.forth.applications Doug Hoffman <glidedog@gmail.com> - 2013-05-24 05:24 -0400
          Re: comp.lang.forth.applications visualforth@rocketmail.com - 2013-05-25 18:12 -0700
        Re: comp.lang.forth.applications "WJ" <w_a_x_man@yahoo.com> - 2013-06-08 11:46 +0000
          Re: comp.lang.forth.applications Doug Hoffman <glidedog@gmail.com> - 2013-06-08 08:55 -0400
        Re: comp.lang.forth.applications "WJ" <w_a_x_man@yahoo.com> - 2013-06-09 19:21 +0000
      Re: comp.lang.forth.applications m.a.m.hendrix@tue.nl - 2013-05-23 23:55 -0700
        Re: comp.lang.forth.applications visualforth@rocketmail.com - 2013-05-25 17:40 -0700
          Re: comp.lang.forth.applications mhx@iae.nl (Marcel Hendrix) - 2013-05-26 09:18 +0200
            Re: comp.lang.forth.applications Paul Rubin <no.email@nospam.invalid> - 2013-05-26 00:24 -0700
            Euler 13 [Was: comp.lang.forth.applications] Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-05-26 02:36 -0500
              Re: Euler 13 Paul Rubin <no.email@nospam.invalid> - 2013-05-26 01:02 -0700
                Re: Euler 13 Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-05-26 06:34 -0500
                Re: Euler 13 Paul Rubin <no.email@nospam.invalid> - 2013-05-26 10:13 -0700
                Re: Euler 13 visualforth@rocketmail.com - 2013-05-26 15:32 -0700
                Re: Euler 13 Paul Rubin <no.email@nospam.invalid> - 2013-05-26 15:40 -0700
              Euler 13 [Was: comp.lang.forth.applications] mhx@iae.nl (Marcel Hendrix) - 2013-05-26 11:06 +0200
                Re: Euler 13 [Was: comp.lang.forth.applications] mhx@iae.nl - 2013-05-26 02:28 -0700
                Re: Euler 13 [Was: comp.lang.forth.applications] "David N. Williams" <williams@umich.edu> - 2013-05-26 10:19 -0400
                Re: Euler 13 [Was: comp.lang.forth.applications] visualforth@rocketmail.com - 2013-05-26 15:24 -0700
                Re: Euler 13 [Was: comp.lang.forth.applications] Coos Haak <chforth@hccnet.nl> - 2013-05-27 01:11 +0200
                Re: Euler 13 [Was: comp.lang.forth.applications] visualforth@rocketmail.com - 2013-05-26 22:36 -0700
                Re: Euler 13 [Was: comp.lang.forth.applications] Alex McDonald <blog@rivadpm.com> - 2013-05-27 01:49 -0700
                Re: Euler 13 [Was: comp.lang.forth.applications] anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-05-27 08:56 +0000
                Re: Euler 13 [Was: comp.lang.forth.applications] "David N. Williams" <williams@umich.edu> - 2013-05-27 08:04 -0400
                Re: Euler 13 [Was: comp.lang.forth.applications] humptydumpty <ouatubi@gmail.com> - 2013-05-27 12:55 -0700
              Re: Euler 13 [Was: comp.lang.forth.applications] albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-05-26 17:24 +0000
                Re: Euler 13 [Was: comp.lang.forth.applications] albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-05-26 17:26 +0000
                Re: Euler 13 Paul Rubin <no.email@nospam.invalid> - 2013-05-26 21:25 -0700
                Re: Euler 13 albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-05-27 12:13 +0000
                Re: Euler 13 Paul Rubin <no.email@nospam.invalid> - 2013-05-27 07:44 -0700
            Re: comp.lang.forth.applications Paul Rubin <no.email@nospam.invalid> - 2013-05-26 01:04 -0700
            Re: comp.lang.forth.applications visualforth@rocketmail.com - 2013-05-26 15:05 -0700
              Re: comp.lang.forth.applications mhx@iae.nl (Marcel Hendrix) - 2013-05-27 01:12 +0200
                Re: comp.lang.forth.applications visualforth@rocketmail.com - 2013-05-26 22:32 -0700
  Re: comp.lang.forth.applications "Ed" <invalid@invalid.com> - 2013-05-24 12:00 +1000
    Re: comp.lang.forth.applications stephenXXX@mpeforth.com (Stephen Pelc) - 2013-05-24 10:16 +0000
      Re: comp.lang.forth.applications "Ed" <invalid@invalid.com> - 2013-05-24 20:44 +1000
        Re: comp.lang.forth.applications Doug Hoffman <glidedog@gmail.com> - 2013-05-24 07:03 -0400
          Re: comp.lang.forth.applications "Ed" <invalid@invalid.com> - 2013-05-27 22:00 +1000
            Re: comp.lang.forth.applications "Elizabeth D. Rather" <erather@forth.com> - 2013-05-27 08:08 -1000
              Re: comp.lang.forth.applications "Ed" <invalid@invalid.com> - 2013-05-29 13:56 +1000
                Re: comp.lang.forth.applications albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-05-29 04:05 +0000
                Re: comp.lang.forth.applications rickman <gnuarm@gmail.com> - 2013-05-29 16:25 -0400
                Re: comp.lang.forth.applications albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-05-30 00:31 +0000
            Re: comp.lang.forth.applications "Paul E. Bennett" <Paul_E.Bennett@topmail.co.uk> - 2013-05-27 23:34 +0100
              Re: comp.lang.forth.applications "Ed" <invalid@invalid.com> - 2013-05-29 13:51 +1000
                Re: comp.lang.forth.applications Alex McDonald <blog@rivadpm.com> - 2013-05-29 00:14 -0700
                Re: comp.lang.forth.applications Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-05-29 04:01 -0500
                Re: comp.lang.forth.applications rickman <gnuarm@gmail.com> - 2013-05-29 16:35 -0400
                Re: comp.lang.forth.applications rickman <gnuarm@gmail.com> - 2013-06-08 22:16 -0400
                Re: comp.lang.forth.applications Brad Eckert <hwfwguy@gmail.com> - 2013-06-10 14:17 -0700
                Re: comp.lang.forth.applications rickman <gnuarm@gmail.com> - 2013-06-10 19:06 -0400
        Re: comp.lang.forth.applications stephenXXX@mpeforth.com (Stephen Pelc) - 2013-05-24 12:30 +0000
          Re: comp.lang.forth.applications the_gavino_himself <visphatesjava@gmail.com> - 2013-05-24 23:14 -0700
          Re: comp.lang.forth.applications rickman <gnuarm@gmail.com> - 2013-05-26 22:18 -0400
      Re: comp.lang.forth.applications Paul Rubin <no.email@nospam.invalid> - 2013-05-24 07:57 -0700
        Re: comp.lang.forth.applications Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-05-24 10:33 -0500
        Re: comp.lang.forth.applications stephenXXX@mpeforth.com (Stephen Pelc) - 2013-05-24 16:34 +0000
          Re: comp.lang.forth.applications Paul Rubin <no.email@nospam.invalid> - 2013-05-24 10:23 -0700
      Re: comp.lang.forth.applications "Paul E. Bennett" <Paul_E.Bennett@topmail.co.uk> - 2013-05-24 20:00 +0100
        Re: comp.lang.forth.applications "Elizabeth D. Rather" <erather@forth.com> - 2013-05-24 09:32 -1000
          Re: comp.lang.forth.applications Paul Rubin <no.email@nospam.invalid> - 2013-05-24 20:18 -0700
            Re: comp.lang.forth.applications "Elizabeth D. Rather" <erather@forth.com> - 2013-05-24 19:31 -1000
  Re: comp.lang.forth.applications oh2aun@gmail.com - 2013-05-23 20:56 -0700
  Re: comp.lang.forth.applications the_gavino_himself <visphatesjava@gmail.com> - 2013-05-24 23:02 -0700
  Re: comp.lang.forth.applications rickman <gnuarm@gmail.com> - 2013-06-08 19:21 -0400

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