If you are a school student and love programming competitions, enjoy solving mathematical and logical problems, designing, and implementing algorithms and data structures – we invite you to participate in the International Olympiad in Informatics — Innopolis Open.
The contest is one of several international Olympiads annually held by Innopolis University. The best high school students from different countries compete in the prestigious competition to sharpen their informatics skills.
3 steps to win!
 Sign up until November 22, 2020 choosing a category: Informatics. For Russian speaking countries, the registration is here
 Pass the Qualification Online Round. There will be 2 independent online contests, you can participate in both contests. The best result of two contests will be taken to get to the Final Stage.

 1st Qualification Online Round: November 22, 2020 at 10:00 a.m. (UTC +3), duration — 5 hours

 2nd Qualification Online Round: December 13, 2020 at 3:00 p.m. (UTC +3), duration — 5 hours
Be on the Final Stage at Innopolis University (we hope it would be onsite, not online) on February 2021, 2021.
I recommend you to participate!
I recommend you to participate too!
Hey 300iq. The
Sign Up
link seems to be broken (both for Russian and other speaking countries). Could you fix it? It redirects to a Codeforces page in russian saying URL not found on server.Fixed, sorry!
Serbia and Montenegro are two separate countries. Can you please fix that?
Is it okay, if we discuss the problem of day1 now? If yes, then can anyone please explain the solution of E for 100?
Answer is at most 4, it's not that hard to check whether the answer is $$$\leq 1$$$, $$$\leq 2$$$ or $$$\leq 3$$$. The harder part is to check whether the answer is zero i.e. there's a nice shape of rooks originally. It can be solved in $$$O(n \sqrt{n} \log{n})$$$. Basically iterate over rows if the row contains $$$\leq \sqrt{n}$$$ rooks perform a bruteforce and note down every pair of columns in that row in a map, if we find a pair that has already occured in another row we found a rectangle. If we have a row with $$$>\sqrt{n}$$$ rooks loop through all the rows and try to find a row with two common columns.
Thanks a lot! Your solution gave me a new way of thinking :D
I have tested this in custom invocation.it gets tle even in 15s.
I just got a mail from the email I used to participate in the qualification round 1. Should I have to sign up again? I am a bit confused.
I signed up to contest in Informatics but there isn't any login id password or any contest link in mine mail or in mine phone. What can i do?
Will any type of editorial would be given for the qualification rounds? If yes, where we may get it?