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Groups > comp.lang.forth > #43292
| From | "WJ" <w_a_x_man@yahoo.com> |
|---|---|
| Newsgroups | comp.lang.forth |
| Subject | Re: Rosetta code binomial coefficient |
| Date | 2015-11-07 08:14 +0000 |
| Organization | A noiseless patient Spider |
| Message-ID | <n1kbs8$n9g$1@dont-email.me> (permalink) |
| References | <4fa62f0c-dab1-4bc0-bbda-8c250a6955d4@googlegroups.com> |
krishna.myneni@ccreweb.org wrote:
> The Forth entry on Rosetta Code for
> computing the binomial coefficient is
> beautiful. Compare its compactness of
> implementation with those in other
> languages. This is a very nice code example
> in Forth. Although it meets the requirements
> of the entry, single integers for 32 bit
> word size quickly lead to failure, e.g. "60
> 30 choose". The implementation is better
> suited for 64-bit word size.
>
> : choose ( n k -- nCk ) 1 swap 0 ?do over i - i 1+ */ loop nip ;
>
> Good job, whoever submitted this to Rosetta Code!
Since only stack operations are performed, it is very difficult
to discern the algorithm.
Ruby:
def choose n,k
(0...k).reduce(1){|t,i| t*(n-i)/(i+1)}
end
choose(8,3)
==>56
choose(22,9)
==>497420
choose(60,30)
==>118264581564861424
choose(99,50)
==>50445672272782096667406248628
choose(200,100)
==>90548514656103281165404177077484163874504589675413336841320
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Rosetta code binomial coefficient krishna.myneni@ccreweb.org - 2015-11-06 22:05 -0800
Re: Rosetta code binomial coefficient mhx@iae.nl - 2015-11-06 23:24 -0800
Re: Rosetta code binomial coefficient Albert van der Horst <albert@spenarnc.xs4all.nl> - 2015-11-07 10:58 +0000
Re: Rosetta code binomial coefficient "WJ" <w_a_x_man@yahoo.com> - 2015-11-07 08:14 +0000
Re: Rosetta code binomial coefficient "WJ" <w_a_x_man@yahoo.com> - 2015-11-07 14:05 +0000
Re: Rosetta code binomial coefficient "WJ" <w_a_x_man@yahoo.com> - 2015-11-15 06:18 +0000
Re: Rosetta code binomial coefficient Paul Rubin <no.email@nospam.invalid> - 2015-11-07 00:23 -0800
Re: Rosetta code binomial coefficient Bernd Paysan <bernd.paysan@gmx.de> - 2015-11-07 15:11 +0100
Re: Rosetta code binomial coefficient krishna.myneni@ccreweb.org - 2015-11-07 07:49 -0800
Re: Rosetta code binomial coefficient krishna.myneni@ccreweb.org - 2015-11-07 08:10 -0800
Re: Rosetta code binomial coefficient Paul Rubin <no.email@nospam.invalid> - 2015-11-07 08:50 -0800
Re: Rosetta code binomial coefficient Bernd Paysan <bernd.paysan@gmx.de> - 2015-11-07 20:20 +0100
Re: Rosetta code binomial coefficient krishna.myneni@ccreweb.org - 2015-11-07 17:45 -0800
Re: Rosetta code binomial coefficient Paul Rubin <no.email@nospam.invalid> - 2015-11-07 19:50 -0800
Re: Rosetta code binomial coefficient "WJ" <w_a_x_man@yahoo.com> - 2015-11-08 15:35 +0000
Re: Rosetta code binomial coefficient "WJ" <w_a_x_man@yahoo.com> - 2015-11-25 20:29 +0000
Re: Rosetta code binomial coefficient Paul Rubin <no.email@nospam.invalid> - 2015-11-25 12:43 -0800
Re: Rosetta code binomial coefficient Bernd Paysan <bernd.paysan@gmx.de> - 2015-11-08 18:51 +0100
Re: Rosetta code binomial coefficient Albert van der Horst <albert@spenarnc.xs4all.nl> - 2015-11-08 18:51 +0000
Re: Rosetta code binomial coefficient Paul Rubin <no.email@nospam.invalid> - 2015-11-08 19:55 -0800
Re: Rosetta code binomial coefficient krishna.myneni@ccreweb.org - 2015-11-08 07:03 -0800
Re: Rosetta code binomial coefficient krishna.myneni@ccreweb.org - 2015-11-09 06:57 -0800
Re: Rosetta code binomial coefficient krishna.myneni@ccreweb.org - 2015-11-10 03:49 -0800
Re: Rosetta code binomial coefficient Ron Aaron <rambamist@gmail.com> - 2015-11-10 14:01 +0200
Re: Rosetta code binomial coefficient krishna.myneni@ccreweb.org - 2015-11-10 19:13 -0800
Re: Rosetta code binomial coefficient Ron Aaron <rambamist@gmail.com> - 2015-11-11 07:38 +0200
Re: Rosetta code binomial coefficient glidedog@gmail.com - 2015-11-14 05:26 -0800
Re: Rosetta code binomial coefficient krishna.myneni@ccreweb.org - 2015-11-14 06:19 -0800
Re: Rosetta code binomial coefficient krishna.myneni@ccreweb.org - 2015-11-14 06:22 -0800
Re: Rosetta code binomial coefficient glidedog@gmail.com - 2015-11-14 08:16 -0800
Re: Rosetta code binomial coefficient krishna.myneni@ccreweb.org - 2015-11-14 11:16 -0800
Re: Rosetta code binomial coefficient "WJ" <w_a_x_man@yahoo.com> - 2016-06-28 00:02 +0000
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