Hi!

On 2014-05-04 17:48, LeppyR64 wrote:
> I didn't participate in this round since I qualified through Round
> 1A.
> 
> In analysis I noticed that a large amount of people near the bubble
> for the top 1000 who got a wrong answer for A Large.  I'm a little
> confused that I fail to see the pitfall after successfully solving
> the small input.

I'm one of those unlucky, because I was too confident about this
"simple" problem (and focused later on the other two problems).

For two strings, the number of moves required to bring a particular
"position" to the same length is the difference between the counts in
the two strings, i. e., for

aaaabb
aabb

two (4 - 2) moves are required to bring aaaa and aa to the same length.

I rushed way too much with the large input and used "maximum number -
minimum number", which is of course wrong.  Instead, one has to find a
common length to bring all pieces to, and then count the difference of
*each* piece to this common length.

In order to minimise the L1-differences, the median should be chosen
as the common length.  This would have been an almost trivial change
to make, but alas.

If I wasn't clear here, let me know and I can try to elaborate in more
detail on something.

Yours,
Daniel

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Done:  Arc-Bar-Cav-Hea-Kni-Ran-Rog-Sam-Tou-Val-Wiz
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