Tasks from the first phase (b) of the Brazilian Olympiad at Informatics (OBI) were released in their official website!
Differently from the previous time, solutions are still being judged, and participants will be able to ask for re-judgment yet, what (I think) may change the tasks/tests. Also, unlike last time, people are already uploading the tasks to neps, so I guess we'll find the portuguese versions there in the next days.
But anyway, I still wanted to
know solutions of the Halloween task play with polygon / continue what I started. And finally, as I think not everybody wants to see this kind of post, I'm moving the contests/announcements to a group (it helps to keep things organized as well). In case I translate the next phases of the olympiad it will be announced there.
Thanks to the people who make OBI this great olympiad, to all my friends at CP for the support, and to Mike Mirzayanov for the amazing codeforces and polygon platforms.
These tasks were presented in different contests based on the classes of the participants. This contest is a merge of all different questions that appeared, and you can find the different versions in the statements section (in portuguese).
Since this is (still) the first phase of the olympiad, the tasks would be too easy for experienced users.
If you find some mistakes, please point that out to me, I will be happy to change them.
I don't have any link with the olympiad and didn't find anywhere that I couldn't do this. But if there is some problem, please tell me.