

Dropbox challenge - ratsbane
http://www.dropbox.com/jobs/challenges

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GoogleMeElmo
The first one is a knapsack problem:
<http://en.wikipedia.org/wiki/Knapsack_problem>

The third on is Zero-sum problem: <http://en.wikipedia.org/wiki/Zero-sum>

Nor sure about the second one. Anyone who knows?

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mayank
The second problem seems open-ended and a test of UX/creativity skills: "There
is no objectively 'right' answer here, and in fact there may be multiple ways
to interpret a provided list of file events."

The third problem is not zero-sum, it's subset-sum:
<http://en.wikipedia.org/wiki/Subset_sum>

I never understood the value of these simplified competitions. If your goal is
to test implementations of approximation algorithms, then at least make the
conditions realistic, like the Netflix prize.

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tel
I think the Netflix prize is a pretty bad comparison since it fueled years of
active research from top machine learning and data mining people. It's great
work, but if you're trying to find new hires the time scale is quite a ways
off.

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mayank
On the contrary, within a few days of the Netflix prize challenge being
launched, a guy put up a detailed blog post with a simple linear algebra
method that could beat Netflix's system at the time (link below). It didn't
come anywhere near the 10% improvement threshold, but it beat Netflix's system
with a handful of lines of C code, and it ran off his laptop. Sounds like he
would have made an excellent hire.

<http://sifter.org/~simon/journal/20061211.html>

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tel
Haha, I stand very well corrected!

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borski
Ha, the first one is cute. It's stolen almost directly from some CS
competition training problems I did back in high school.

I saw it and _knew_ I'd seen it before. ;)

(edited to remove the name of the competition, since it turns out some answers
are Googleable :-\\)

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Havoc
1st one just screams Genetic Algo. Maybe thats just a case of "When you have a
hammer..." though. I don't see any CPU/time limit though so maybe there is a
proper solution.

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mayank
You're right about the "when you have a hammer" issue. The biggest problem
with genetic algorithms is that there's rarely a good reason for using them
for cookie-cutter combinatorial optimization like the problem, when there are
hundreds of papers on very good approximation algorithms.

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ericmsimons
This reminds me of what Facebook just recently started doing. I remember
reading an article about how Facebook's plan failed though (regarding the
hackathon)

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kalmi10
Facebook started Facebook Puzzles long time ago.
<http://www.facebook.com/careers/puzzles.php>

Facebook's Hackation has very little to do with these challenges. Btw why was
Hackation a failure?

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abraham
"mexican-coke". That doesn't sound very legal...

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jrockway
It's a popular cola that's sweetened with sucrose.

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abraham
It is call sarcasm. People on the internet use it all the time.

