Thank you all for participating in the elimination round of Bayan Contest. The final results are available. We had more than three thousand registered users for the contest on Codeforces and one third of them were able to solve at least one problem. In the meantime 1100 Iranian contestants participated in our local contest and half of them solved a problem.
We tried hard to prepare a challenging-yet-fun problemset.
The problem "241G - Challenging Balloons" was inspired from a real story! The problem described in the story was used in CEOI 2011 (Task Balloons), and the provided algorithm was the author's solution during that contest — which got the full mark indeed.
According to statistics, "241D - Numbers" was the hardest problem. A tricky approach to the solution is to ignore large inputs and solve the problem for small values of n. You may observe that it is possible to find the demanded subset within a small part of input. During the contest, no one solved all the problems but there was at least one successful attempt for each of them.
We hope you enjoyed it all!
As stated before, Top 100 contestants will be receiving T-shirts. So, update your contact information and T-Shirt size in your Codeforces profile. We'll start sending the prizes as soon as possible.
And the winners...
The winners will receive invitation letters — to the on-site event — soon. If you are one of them make sure your contact information is up-to-date.
Congratulations to all the participants, specially the winners. See you in Tehran!