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Re: project euler problems in forth

From "WJ" <w_a_x_man@yahoo.com>
Newsgroups comp.lang.forth
Subject Re: project euler problems in forth
Date 2013-03-12 00:46 +0000
Organization A noiseless patient Spider
Message-ID <khltt8$v2f$1@dont-email.me> (permalink)
References <2f19628a-24d6-4480-85af-f081e9208643@googlegroups.com>

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> What is the value of the first triangle number to have over five
> hundred divisors?
> 
> 012.fs
> 
> #! /usr/bin/gforth
> 
> 500 constant numfactors
> 
> : get_num_divisors ( n -- divisors )
> 0 swap 1 ( start with divisor of 1 ) 
> begin
>     2dup mod 0= ( check for n mod k )
>     if
>       rot 1+ rot rot
>     then
>   2dup dup * > ( check for k*k > n)
> while
>   1+
> repeat
> 2drop 2*
> ;
> 
> : pe012
> 0 1 
> begin 
>   dup rot + dup
>   get_num_divisors
>   numfactors <
> while
>   swap 1+
> repeat      
> swap drop . cr
> ;
> 
> pe012

Factor:

USING: math.primes.factors ;

: prob12 ( -- n )
  2 "next" set
  1
  [ dup divisors length 500 > ]
  [ "next" get +  "next" inc ]
  until
;

prob12 .
76576500

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project euler problems in forth bob wilkinson <wilkinson.bob@gmail.com> - 2013-03-11 03:25 -0700
  Re: project euler problems in forth m.a.m.hendrix@tue.nl - 2013-03-11 04:32 -0700
  Re: project euler problems in forth "WJ" <w_a_x_man@yahoo.com> - 2013-03-11 11:31 +0000
    Re: project euler problems in forth "WJ" <w_a_x_man@yahoo.com> - 2013-06-14 15:50 +0000
  Re: project euler problems in forth "WJ" <w_a_x_man@yahoo.com> - 2013-03-11 12:13 +0000
    Re: project euler problems in forth "WJ" <w_a_x_man@yahoo.com> - 2013-03-11 12:26 +0000
      Re: project euler problems in forth Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-03-11 10:13 -0500
        Re: project euler problems in forth Doug Hoffman <glidedog@gmail.com> - 2013-03-11 11:34 -0400
          Re: project euler problems in forth The Beez <the.beez.speaks@gmail.com> - 2013-03-11 14:43 -0700
            Re: project euler problems in forth Doug Hoffman <glidedog@gmail.com> - 2013-03-12 04:50 -0400
  Re: project euler problems in forth Zbiggy <zbigniew2011REMOVE@gmail.REMOVE.com> - 2013-03-11 12:46 +0000
    Re: project euler problems in forth Zbiggy <zbigniew2011REMOVE@gmail.REMOVE.com> - 2013-03-11 12:56 +0000
  Re: project euler problems in forth albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-03-11 12:43 +0000
  Re: project euler problems in forth "WJ" <w_a_x_man@yahoo.com> - 2013-03-11 12:49 +0000
    Re: project euler problems in forth "WJ" <w_a_x_man@yahoo.com> - 2013-03-11 19:44 +0000
  Re: project euler problems in forth "WJ" <w_a_x_man@yahoo.com> - 2013-03-11 13:54 +0000
  Re: project euler problems in forth "WJ" <w_a_x_man@yahoo.com> - 2013-03-11 20:04 +0000
    Re: project euler problems in forth "WJ" <w_a_x_man@yahoo.com> - 2013-07-06 05:31 +0000
  Re: project euler problems in forth "WJ" <w_a_x_man@yahoo.com> - 2013-03-11 20:19 +0000
  Re: project euler problems in forth "WJ" <w_a_x_man@yahoo.com> - 2013-03-11 20:44 +0000
  Re: project euler problems in forth "WJ" <w_a_x_man@yahoo.com> - 2013-03-11 23:00 +0000
    Re: project euler problems in forth "WJ" <w_a_x_man@yahoo.com> - 2013-07-06 05:47 +0000
  Re: project euler problems in forth "WJ" <w_a_x_man@yahoo.com> - 2013-03-12 00:15 +0000
  Re: project euler problems in forth "WJ" <w_a_x_man@yahoo.com> - 2013-03-12 00:46 +0000
  Re: project euler problems in forth "WJ" <w_a_x_man@yahoo.com> - 2013-03-12 01:06 +0000
    Re: project euler problems in forth "WJ" <w_a_x_man@yahoo.com> - 2013-07-06 06:13 +0000
  Re: project euler problems in forth "WJ" <w_a_x_man@yahoo.com> - 2013-03-12 02:29 +0000
    Re: project euler problems in forth "WJ" <w_a_x_man@yahoo.com> - 2013-06-18 10:44 +0000
    Re: project euler problems in forth "WJ" <w_a_x_man@yahoo.com> - 2013-07-06 05:51 +0000
  Re: project euler problems in forth "WJ" <w_a_x_man@yahoo.com> - 2013-03-12 03:09 +0000
    Re: project euler problems in forth "WJ" <w_a_x_man@yahoo.com> - 2013-06-18 16:16 +0000
      Re: project euler problems in forth "WJ" <w_a_x_man@yahoo.com> - 2013-06-18 16:21 +0000
  Re: project euler problems in forth "WJ" <w_a_x_man@yahoo.com> - 2013-03-12 09:45 +0000
    Re: project euler problems in forth "WJ" <w_a_x_man@yahoo.com> - 2013-06-18 11:51 +0000
    Re: project euler problems in forth "WJ" <w_a_x_man@yahoo.com> - 2013-07-06 05:53 +0000

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