Re: A86: Lookup tables


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Re: A86: Lookup tables




David Phillips wrote:

> No, he is skipping half, plus adding on the duplicates, as he said earlier.
>
> At 08:58 PM 6/3/98 -0400, you wrote:
> >
> >Jimmy Mårdell wrote:
> >
> >> At 22:47 1998-06-02 EDT, you wrote:
> >> >Wouldn't fetching the answer in itself involve multiplication?  I'm
> >> >having trouble thinknig of how to explain this, but how would you be able
> >> >to know where to look in the table without multiplication?
> >>
> >> No. It's not that easy though, if you decide to skip half of
> >> the lookup table:
> >>
> >>     0  1  2  3  4  5  6  7  8  9
> >>  ---------------------------------
> >> 0   0  0  0  0  0  0  0  0  0  0
> >> 1      1  2  3  4  5  6  7  8  9
> >> 2         4  6  8 10 12 14 16 18
> >> 3            9 12 15 18 21 24 27
> >>
> >
> >That's not skipping exactly half.  You are skipping a little less than half,
> >but close enough. :)

Ok.  In a full table you would have a*b and b*a .. so you can skip b*a because it
is the same as a*b.  But what happens when a=b?  You have a*a and there is only
one entry for that, not two.  So you can't skip those.  That is what you mean
right?

--
Bryan Rabeler <brabeler@ticalc.org>
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