300iq's blog

By 300iq, 2 months ago, In English

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 on-site, not online) on February 20-21, 2021.

 
 
 
 
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2 months ago, # |
Rev. 2   Vote: I like it +21 Vote: I do not like it

I recommend you to participate!

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2 months ago, # |
  Vote: I like it +8 Vote: I do not like it

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.

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2 months ago, # |
  Vote: I like it +13 Vote: I do not like it

Serbia and Montenegro are two separate countries. Can you please fix that?

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2 months ago, # |
  Vote: I like it +11 Vote: I do not like it

Is it okay, if we discuss the problem of day-1 now? If yes, then can anyone please explain the solution of E for 100?

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    2 months ago, # ^ |
      Vote: I like it +41 Vote: I do not like it

    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.

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      2 months ago, # ^ |
        Vote: I like it 0 Vote: I do not like it

      Thanks a lot! Your solution gave me a new way of thinking :D

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7 weeks ago, # |
  Vote: I like it 0 Vote: I do not like it
Weak test data in problem E.I was coding nroot(n)*log(n) solution for E and made a stupid bug but my code got AC and I realized that it should get tle.so I wrote quadratic solution(for checking if answer 0) and that also got AC without breaking if answer=0.
Test Case- 
n=50000
1,1
1,2
2,1
2,2
..
..
..
25000,1
25000,2

code — https://ideone.com/JmcEtB

I have tested this in custom invocation.it gets tle even in 15s.

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6 weeks ago, # |
  Vote: I like it +17 Vote: I do not like it

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.

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6 weeks ago, # |
  Vote: I like it 0 Vote: I do not like it

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?

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5 weeks ago, # |
  Vote: I like it +16 Vote: I do not like it

Will any type of editorial would be given for the qualification rounds? If yes, where we may get it?