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Re: Factorial and large numbers.

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Stephen Turner
August 9, 2002 00:46
Re: Factorial and large numbers.
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On Fri, 9 Aug 2002, Markus Laire wrote:

> >>$z=pop;sub g{vec"\x10\xd7\xa9\x98b\xef",pop,2}
> >>print$z<2||(1+g$z%25)*(1,3,2,4)[g 24-$z/25%25]*6*(1+g$z/625)%10,$/ 
> >> Has anyone else tried lookup instead of computing n!. I'd like to 
> >> know shortest possible solution for this sub-problem also.
> > For a general direct method, see
> >
> That seems to be allmost the same lookup method I came up with, 
> except that it uses unnecessary large table (100 items instead of 25) 
> and base 5 instead of 25 which doubles the steps.

See the bottom of for another
method that only uses one lookup table. I too concluded that any such method
was too long though.

Stephen Turner, Cambridge, UK
"This is Henman's 8th Wimbledon, and he's only lost 7 matches." BBC, 2/Jul/01

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