Re: [FWP] Interleaving arrays

[tomr@aceldama.com]

On Thu, Nov 11, 1999 at 01:00:25PM -0600, eric wrote:
> This one works:
> @cats = @cats[map (($_/2 + ($_ % 2) * ($#cats/2 + 1)), 0..$#cats)];
> 
> But this one is cleaner:
> @cats = @cats[map (($_/2 + ($_ % 2) * ($#cats+1)/2 ), 0..$#cats)]

I think I'd write the two changing parts as:
    (1+($#cats/2))
    ((1+$#cats)/2)
... just to make the two lines the same length :)

> Everyone see why?

In the former case we're dividing by two (possibly giving a fractional
answer) then adding 1, but in the latter case we're adding two
integers (giving an integer) then dividing by 2 (possibly giving a
fraction). So there's $#cats/2 less non-integer calculations.

That's what I see.

Tom

-- 
--    Tom Rathborne    tomr@aceldama.com
--                     http://www.aceldama.com/~tomr/
--    "I seem to be having tremendous difficulty with my life-style."

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