Edvard's blog

By Edvard, history, 3 years ago, translation, In English,

Hi, Codeforces!

Educational Codeforces Round 3 will take place on 19 December 2015 at 18:00 MSK for the first and second divisions. You can read about educational rounds here and here. A lot of time have passed since the previous round. I hope that the next rounds will be more regular.

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The round will be unrated for all users and it will be held with extented ACM ICPC rules. You will have two hours to solve six problems. After that you will have one day to hack any solution you want. You will have access to copy any solution and test it locally.

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This time the round was prepared not only by me, Edvard Davtyan. Firstly, thanks a lot to Alexey Dergunov dalex who shared one of his problems with well-known idea. Also thanks a lot to Alexandr Frolov fcspartakm, Vitaliy Kudasov kuviman and Arthur Svechnikov ikar for their help in preparing problems. MikeMirzayanov helped us to invent the problems. Also thanks a lot to Maria Belova Delinur for translating the problems from my RussianEnglish to English :-)

I hope you will enjoy the problems.

Good luck and have fun!

UPD1: The first part of competition is over. I hope that you enjoyed the problems. Now you let's hack other solutions :-)

UPD2: The editorial is ready.

UPD3: The round is over. All solutions are rejudged on full testset. The results are final.

UPD4: 6725 rows affected :-)

 
 
 
 
  • Vote: I like it  
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3 years ago, # |
  Vote: I like it -29 Vote: I do not like it

Do you mean from RussianEnglish to EnglishRussian????!!

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3 years ago, # |
  Vote: I like it +19 Vote: I do not like it

Move back the contest maybe? COCI is one hour before this one.

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3 years ago, # |
  Vote: I like it 0 Vote: I do not like it

As far as I understand, upsolving will be available only tomorrow. Am I right?

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    3 years ago, # ^ |
    Rev. 2   Vote: I like it 0 Vote: I do not like it

    I dont think so. I managed to submit my solution for D (Sad part is it got accepted :( ) . Still don't know whether the tests are final !!!

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3 years ago, # |
  Vote: I like it +4 Vote: I do not like it

when will be start hacking system?

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3 years ago, # |
  Vote: I like it +18 Vote: I do not like it

It's horrible to participate at two contests at the same time ...

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3 years ago, # |
Rev. 3   Vote: I like it -8 Vote: I do not like it

this comment was deleted

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3 years ago, # |
  Vote: I like it +3 Vote: I do not like it

I spent a lot of time on F thinking that each mosquito is landing from infinity and it'll be caught on the way down in the first point it'll intersect a circle made by a frog! -_-

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3 years ago, # |
  Vote: I like it +9 Vote: I do not like it

What it means actually?

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3 years ago, # |
  Vote: I like it +10 Vote: I do not like it

What does "Unexpected verdict" means in hack verdict?

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    3 years ago, # ^ |
      Vote: I like it -8 Vote: I do not like it

    My guess: the validator or reference solution crashed?

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      3 years ago, # ^ |
        Vote: I like it +3 Vote: I do not like it

      Or maybe the checker of the correction of the testcase.

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      3 years ago, # ^ |
      Rev. 3   Vote: I like it +15 Vote: I do not like it

      Validator and reference solution is ok. The problem in other two solutions that was tagged as CORRECT, but got WRONG_ANSWER on that test. I've changed the tag for that solutions. Hacks will be rejudged soon.

      com.codeforces.contester.exception.ChallengedCorrectSolutionsException: There are challenged correct solutions: ikar_nlog.cpp: WRONG_ANSWER ikar_nlog2.cpp: WRONG_ANSWER

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    3 years ago, # ^ |
      Vote: I like it 0 Vote: I do not like it

    All three your hacks with unknown verdict was rejudged.

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3 years ago, # |
  Vote: I like it 0 Vote: I do not like it

Seeing the verdict for the first time! Should not it be TLE? It is mainly for _getch() I think.

I am talking about this submission: 14881737

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    3 years ago, # ^ |
      Vote: I like it +17 Vote: I do not like it

    Idleness limit exceeded means that your solution does not doing anything and not using processor time. For example it's waiting for input from keyboard.

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3 years ago, # |
  Vote: I like it 0 Vote: I do not like it
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3 years ago, # |
Rev. 3   Vote: I like it -8 Vote: I do not like it

the problem E didn't require a connected graph,so i should be able to hack the solutions with unconnected graphs. for example 5 4 1 2 1 3 4 1 1 5 1 2 5 1 is a satisfied test.

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    3 years ago, # ^ |
      Vote: I like it +33 Vote: I do not like it

    The first word in the problem statement is 'Connected'...

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      3 years ago, # ^ |
        Vote: I like it +14 Vote: I do not like it

      so sorry for being such careless. thanks for replying.

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3 years ago, # |
  Vote: I like it +11 Vote: I do not like it

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3 years ago, # |
Rev. 2   Vote: I like it 0 Vote: I do not like it

Please leave some room for err on A,B and C in these educational rounds ! :]

They protect contestants from overflow and multiplying by zero by default, which makes their solutions almost unable to hack(&prevent learning probably).

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    3 years ago, # ^ |
    Rev. 2   Vote: I like it -18 Vote: I do not like it

    Why there is just negative feedback ? I thought maybe in this way both sides of hack action would be more precise about their work. cause these rounds are all for learning

    If it's wrong , sorry for stating that


    UPDT: mentioned down votes have been neutralized so far, self_reply in complain gets downed now :}

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3 years ago, # |
  Vote: I like it 0 Vote: I do not like it

How can I obtain test8 for D?