Iteration for Factorials

mensanator at aol.com mensanator at aol.com
Mon Oct 22 19:57:25 CEST 2007


On Oct 22, 7:50 am, Duncan Booth <duncan.bo... at invalid.invalid> wrote:
> Py-Fun <lorna.bu... at gmail.com> wrote:
> > I'm stuck trying to write a function that generates a factorial of a
> > number using iteration and not recursion.  Any simple ideas would be
> > appreciated.
>
> This version avoids doing anything fancier than adding 1, so it should be
> simple enough for anyone:
>
> def factorial(e):
>     a = 1
>     for b in range(e):
>         c = 0
>         for j in range(b, -1, -1):
>             for d in range(a):
>                 c += 1
>         a = c
>     return a

Not simple enough for my taste:

>>> import gmpy
>>> gmpy.fac(10)
mpz(3628800)




More information about the Python-list mailing list