Well, this was a long wait for every participant of this challenge.

I entry the contest in April, and the winner has been announced yesterday by Iggy Fernandez and Chen Shapira.

It was indeed an amazing challenge and I thanks everyone who brought this up.

It was also the key factor for me to open this blog to publish my solution and more and more things around SQL and relational databases.

The Winner !

Alberto Dell’Era took the first place not with his incredible Fast Fourier Transform O(n^log(n)) complexity, but the other one using Discret Fourier Transform.
In his FFT solution he used the model clause with iterative arguments and the jury saw it has not being straithforward SQL.

But he still have his DFT solution, which still perform very well in O(n^2) (and which is also more accessible).

Be sure to check both his solutions !

The Runner up !

The runner up is André Aurajo !
His solution was my favorite for the challenge maybe because I understand it very well both the logic and the SQL.

I’m not sure about the complexity : according to his performance graphic, it seems O(k^n) with k very close to 1.00

I think his solution is the one I would have found by myself !
I’m sure the same clever logic could be reused for more problems !

Conclusion

I’m happy about the whole challenge. Simple statement, great great solutions, fast writing, fast performing, XML tricks.

My own solution was somewhere between O(n^(k-1)) and O(n^k) complexity, with k being the number of faces of the dice.
I couldn’t run test past 72 dices throws, I was already on the ten minutes mark !

However, it was Chen Shapira’s favorite !

As she pointed out, I noticed during testing some differences between Oracle and SQL Server.
After reading again my post, damn it’s not very understandable. I’m still a beginner in the blogging world and I have room for improvements.

I will write a v2 version of this topic with full queries ready to run, but not before coming back from holidays !