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Groups > comp.lang.forth > #27428

Re: Josephus Circle problem

Newsgroups comp.lang.forth
Date 2013-12-24 05:01 -0800
References <7x61qfuel8.fsf@ruckus.brouhaha.com>
Message-ID <03b7bcda-141f-464d-87bf-4151a56fe36e@googlegroups.com> (permalink)
Subject Re: Josephus Circle problem
From ForthFreak <forthfreak@gmail.com>

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With a slight change to use PAD. This allows one to try different circle sizes without need for re-compilation.

0 value #soldiers
#soldiers value remain
0 value position

: init ( --) 
    #soldiers 0 do 1  pad i +  c!  loop 
    -1 to position  #soldiers to remain ;
    
: soldiers' ( -- addr) pad position + ;
    
: position++ ( --)
    position 1+ #soldiers mod to position ;
    
: kill3rd ( --) 
    0 begin 
        position++  soldiers' c@ if 1+ then
      dup 3 = until drop 
      0 soldiers' c!  position 1+ .  remain 1- to remain ;
    
: killThem ( --) init begin remain 0> while kill3rd repeat 
    cr ." Last man standing at position " position 1+ . ;

: victims ( n -- ) to #soldiers  killThem ;



40 victims
Last man standing at position 28

12 victims
Last man standing at position 10

100 victims
Last man standing at position 91

etc

Okay, that's enough Forth for Christmas eve ;-)

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Thread

Josephus Circle problem Paul Rubin <no.email@nospam.invalid> - 2013-12-23 19:12 -0800
  Re: Josephus Circle problem "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-12-24 02:49 -0500
    Re: Josephus Circle problem Paul Rubin <no.email@nospam.invalid> - 2013-12-24 01:13 -0800
      Re: Josephus Circle problem mhx@iae.nl - 2013-12-24 02:17 -0800
        Re: Josephus Circle problem ForthFreak <forthfreak@gmail.com> - 2013-12-24 03:45 -0800
          Re: Josephus Circle problem Paul Rubin <no.email@nospam.invalid> - 2013-12-24 04:25 -0800
            Re: Josephus Circle problem ForthFreak <forthfreak@gmail.com> - 2013-12-24 04:25 -0800
              Re: Josephus Circle problem Paul Rubin <no.email@nospam.invalid> - 2013-12-24 04:52 -0800
            Re: Josephus Circle problem albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-12-24 14:57 +0000
            Re: Josephus Circle problem "Ed" <invalid@invalid.com> - 2013-12-25 20:15 +1100
          Re: Josephus Circle problem mhx@iae.nl - 2013-12-24 04:36 -0800
      Re: Josephus Circle problem "Rod Pemberton" <dont_use_email@xnohavenotit.cnm> - 2013-12-24 17:05 -0500
      Re: Josephus Circle problem "WJ" <w_a_x_man@yahoo.com> - 2014-03-10 07:11 +0000
    Re: Josephus Circle problem mhx@iae.nl - 2013-12-24 02:59 -0800
  Re: Josephus Circle problem ForthFreak <forthfreak@gmail.com> - 2013-12-24 01:53 -0800
    Re: Josephus Circle problem Paul Rubin <no.email@nospam.invalid> - 2013-12-24 04:06 -0800
      Re: Josephus Circle problem ForthFreak <forthfreak@gmail.com> - 2013-12-24 04:24 -0800
  Re: Josephus Circle problem ForthFreak <forthfreak@gmail.com> - 2013-12-24 04:30 -0800
    Re: Josephus Circle problem ForthFreak <forthfreak@gmail.com> - 2013-12-24 04:35 -0800
  Re: Josephus Circle problem ForthFreak <forthfreak@gmail.com> - 2013-12-24 05:01 -0800
    Re: Josephus Circle problem Paul Rubin <no.email@nospam.invalid> - 2013-12-24 05:34 -0800
      Re: Josephus Circle problem ForthFreak <forthfreak@gmail.com> - 2013-12-24 05:22 -0800
      Re: Josephus Circle problem "Elizabeth D. Rather" <erather@forth.com> - 2013-12-24 13:25 -1000
        Re: Josephus Circle problem "Ed" <invalid@invalid.com> - 2013-12-25 20:40 +1100
          Re: Josephus Circle problem "Elizabeth D. Rather" <erather@forth.com> - 2013-12-25 09:37 -1000
            Re: Josephus Circle problem ForthFreak <forthfreak@gmail.com> - 2013-12-26 03:19 -0800
              Re: Josephus Circle problem "Elizabeth D. Rather" <erather@forth.com> - 2013-12-26 12:01 -1000
            Re: Josephus Circle problem "Ed" <invalid@invalid.com> - 2013-12-27 12:33 +1100
              Re: Josephus Circle problem Elizabeth D Rather <erather@forth.com> - 2013-12-26 17:41 -1000
                Re: Josephus Circle problem "Ed" <invalid@invalid.com> - 2013-12-27 18:46 +1100
                Re: Josephus Circle problem Mark Wills <markrobertwills@yahoo.co.uk> - 2013-12-27 02:46 -0800
                Re: Josephus Circle problem albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-12-27 13:16 +0000
                Re: Josephus Circle problem mhx@iae.nl - 2013-12-27 05:27 -0800
                Re: Josephus Circle problem albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-12-27 14:15 +0000
                Re: Josephus Circle problem "Ed" <invalid@invalid.com> - 2013-12-29 21:56 +1100
                Re: Josephus Circle problem albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-12-29 12:37 +0000
                Re: Josephus Circle problem "Ed" <invalid@invalid.com> - 2013-12-30 00:47 +1100
                Re: Josephus Circle problem "Ed" <invalid@invalid.com> - 2013-12-29 14:08 +1100
              Re: Josephus Circle problem Mark Wills <markrobertwills@yahoo.co.uk> - 2013-12-27 02:35 -0800
                Re: Josephus Circle problem Mark Wills <markrobertwills@yahoo.co.uk> - 2013-12-27 02:43 -0800
                Re: Josephus Circle problem albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-12-27 19:00 +0000
    Re: Josephus Circle problem albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-12-24 15:59 +0000
  Re: Josephus Circle problem Gerry Jackson <spam@qlikz.org> - 2013-12-24 20:07 +0000
    Re: Josephus Circle problem albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-12-24 20:31 +0000
    Re: Josephus Circle problem mhx@iae.nl - 2013-12-25 04:38 -0800
      Re: Josephus Circle problem mhx@iae.nl - 2013-12-25 06:04 -0800
      Re: Josephus Circle problem mhx@iae.nl - 2013-12-25 06:06 -0800
        Re: Josephus Circle problem Paul Rubin <no.email@nospam.invalid> - 2013-12-25 23:08 -0800
          Re: Josephus Circle problem ForthFreak <forthfreak@gmail.com> - 2013-12-26 03:31 -0800
        Re: Josephus Circle problem Gerry Jackson <spam@qlikz.org> - 2013-12-26 10:52 +0000
          Re: Josephus Circle problem Tristan Plumb <firth@trstn.net> - 2013-12-26 14:37 +0000
            Re: Josephus Circle problem Paul Rubin <no.email@nospam.invalid> - 2013-12-26 07:12 -0800
          Re: Josephus Circle problem Gerry Jackson <spam@qlikz.org> - 2013-12-26 17:31 +0000
        Re: Josephus Circle problem Ron Aaron <rambamist@gmail.com> - 2013-12-26 21:39 +0200
    Re: Josephus Circle problem anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-12-26 17:33 +0000

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