hn21b=: 3 : 0
i=. 0
m=. 2 3 5x
z=. 1x
for. i.<:y do.
z=. z , a=. <./ m
b=. a = m
i=. i + b
m=. (m*-.b) + (b*2 3 5) * i{z
end.
z
)
----- Original Message -----
From: "R.E. Boss" <[email protected]>
Date: Tuesday, January 5, 2010 21:39
Subject: Re: [Jprogramming] Rosetta code: hamming numbers
To: 'Programming forum' <[email protected]>
> See
> http://www.jsoftware.com/jwiki/RE%20Boss/J-blog/HN for more
> information.
>
> R.E. Boss
>
>
> -----Oorspronkelijk bericht-----
> Van: [email protected]
> [mailto:[email protected]] Namens Sherlock, Ric
> Verzonden: dinsdag 5 januari 2010 22:29
> Aan: Programming forum
> Onderwerp: Re: [Jprogramming] Rosetta code: hamming numbers
>
> Here is another idea for calculating hamming numbers
> ([: /:~ [: ,@:(*/"0 1)/ 2 3 5x&(^"0 1)) i.40
>
> The next step is to work out how big the integer list needs to
> be for a
> given problem
> >:@>....@%: y is a quick & dirty solution but seems to work.
>
> hamming2=: <: { ([: /:~ [: ,@:(*/"0 1)/ 2 3 5x&(^"0
> 1))@(i.@>:@>....@%:@(>./))
> hamming2 >:i.20
> 1 2 3 4 5 6 8 9 10 12 15 16 18 20 24 25 27 30 32 36
> hamming2 1691
> 2125764000
>
> - doesn't solve the 1e6 problem though
>
> > -----Original Message-----
> > From: [email protected] [mailto:programming-
> > [email protected]] On Behalf Of Aai
> > Sent: Wednesday, 6 January 2010 06:17
> > To: Programming forum
> > Subject: [Jprogramming] Rosetta code: hamming numbers
> >
> > J-ers and RC-ers,
> >
> > I entered a solution for this task:
> > http://rosettacode.org/wiki/Hamming_numbers .
> >
> > hamming =: {. (/:~...@~.@] , 2 3 5 * {)/ @ (1x ,~ i...@-)
> >
> >
> > However the problem is (which I didn't realize while entering my
> > solution) producing the millionth hamming number. So if anyone
> has a
> > better idea on this, go ahead. Of course it's also a challenge
> to come
> > up with a very J-ish solution for this problem.
> >
> > R.E.Boss perhaps? I used your solution HN00 and it produced
> the answer
> > in ca. 47 sec on my computer.
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