csacademy's blog

By csacademy, 9 days ago, In English,

Hello, Codeforces!

We're going to host a new contest at csacademy.com. Round #52 will take place on Wednesday, 11/October/2017 15:05 (UTC). This contest will be a Div1 + Div2, with 7 tasks of varying difficulty that need to be solved in 2 hours.

We are glad to have HellKitsune as a problem author.

Contest format change

  • The last problem will become visible only 20 minutes after the contest starts.

Contest format:

  • You will have to solve 7 tasks in 2 hours.
  • There will be full feedback throughout the entire contest.
  • Tasks will not have partial scoring, so you need to pass all test cases for a solution to count (ACM-ICPC-style).
  • Tasks will have dynamic scores. According to the number of users that solve a problem the score will vary between 100 and 1000.
  • Besides the score, each user will also get a penalty that is going to be used as a tie breaker.

Prizes

We're going to award the following prizes:

  1. First place: 100$
  2. Second place: 50$

About the penalty system:

  • Computed using the following formula: the minute of the last accepted solution + the penalty for each solved task. The penalty for a solved task is equal to log2 (no_of_submissions) * 5.
  • Solutions that don't compile or don't pass the example test cases are ignored.
  • Once you solve a task you can still resubmit. All the following solutions will be ignored for both the score and the penalty.

If you find any bugs please email us at contact@csacademy.com

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  • Vote: I like it  
  • +92
  • Vote: I do not like it  

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8 days ago, # |
  Vote: I like it +69 Vote: I do not like it

"The last problem will become visible only 20 minutes after the contest starts."

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    8 days ago, # ^ |
      Vote: I like it +13 Vote: I do not like it

    We're testing this new feature and we need to do it in a real contest. We'll revert back next round, probably.

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

      I cant seems to access any problem other than A.

      EDIT: it's working now

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    7 days ago, # ^ |
      Vote: I like it +49 Vote: I do not like it

    Maybe they are still preparing it.

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7 days ago, # |
  Vote: I like it +5 Vote: I do not like it

Just a reminder, the round starts in 2 hours.

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7 days ago, # |
  Vote: I like it +13 Vote: I do not like it

Good luck to all participants!

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7 days ago, # |
  Vote: I like it +36 Vote: I do not like it

Is it rated? I ask because ratings are still not updated. Would be a shame to be unrated because of issues with interactive problem :/

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    7 days ago, # ^ |
      Vote: I like it 0 Vote: I do not like it

    It is rated. We need to fix some issues with people getting penalty for sources that didn't pass the examples, but their submissions still counted. After fixing this, we'll run the rating algorithm and create the virtual contest.

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      5 days ago, # ^ |
        Vote: I like it +18 Vote: I do not like it

      Huh, I see that rating formulas must be pretty bad. Um_nik is a leader in overall ranking and he participated in last contest and took 20th place. 20th place in CSA is I guess equivalent performance to something like 60th on CF. And he got -3 to his rating. Can you imagine tourist taking 60th place on CF and his rating not changing? Does overall rating measure who participated in largest number of contests? Good rating formulas are always pretty hard to come up with :D

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6 days ago, # |
Rev. 3   Vote: I like it 0 Vote: I do not like it

Hello, I still have doubts in correctness of checker of D. Can somebody look at it please?

http://codeforces.com/contest/869/submission/31270592 — my solution, that gets WA

http://codeforces.com/contest/869/submission/31270597 — testing my solution on all possible (0 ≤ a ≤ 99, 0 ≤ b ≤ 99) and it always gives answer 2 for number of black cells.

UPD: Missed the thing, that we can't hit the same cell twice. Sorry.