LOGO-L> Re: factorials

[Yehuda Katz <yehuka@beitberl.beitberl.ac.il>]

George Mills wrote:
> 
> Note that it does not help that much improving the compute_facts
> because it is now dominated by the compare and fact lookups
> once the cache was added.
> 
> Interestingly the code actually looks cleaner with this optimization.
> It certainly helps performance but not as much as you might of
> hoped for.
> 
> Also note the one line of code I changed below for the purist.
> Although some purists might like it the way you had it.

> >
> > ===================================================
> > to main
> > compute_facts
> > solve
> > end
> >
> > to compute_facts
> > make "fact_array(array 10 0)
> > setitem 0 :fact_array 1
> > for[i 1 9][
> >     setitem :i :fact_array :i*item :i-1 :fact_array]
> 
>       setitem :i :fact_array :i*fact :i-1]  <===========
> 
> > end
> >
> > to solve
> > for[num 100 666][
> > if equalp :num(sum fact item 1 :num
> >                    fact item 2 :num
> >                    fact item 3 :num)
> >    [pr :num]]
> > end
> >
> > to fact :n
> > op item :n :fact_array
> > end
> > ===================================================

George,

I find your suggestion (I put an "arrow" next to it) to be a good one,
though I might belong to the "purist" party.

If my suggestion above save some time or not, is at this moment less
important.

Regards...

[[Yehuda]]

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