Mock CCC '20 Contest 1 Senior

Hello, welcome to a mock CCC! Here are the parameters of the contest:

  • Contestants must write the mock CCC under CCC rules. Notably, contestants may not consult the Internet outside of accessing the relevant parts of the contest via the DMOJ platform or consulting language documentation, and contestants may not use any prewritten code.
  • Contest duration: 3 hours.
  • Number of problems: 5, full feedback, with subtasks. The problems follow the CCC format of being worth 15 marks each. All problems have explicit subtasks.
  • Format: IOI (no penalties, no tiebreakers)
  • Not rated.
  • Scoreboard will be hidden.
  • Number of submissions allowed per problem: 50.
  • The problem writers for this contest are ChrisT, Plasmatic and c

Clarification requests for the contest must be routed through the clarification system provided on DMOJ, and not through other channels including but not limited to Slack. Furthermore, all clarification requests will be handled the way they normally are in IOI. Note that, in particular, clarification requests must come in the form of yes/no questions.

Due to rampant issues with cheating on contests that has happened recently, suspicious behavior may lead to penalties. Such behavior includes, but is not limited to:

  • Registering for the contest with at least two accounts.
  • Participating in the contest with an account that is not your primary account.
  • During the contest window, talking about the contest in more detail than answering a yes/no question about whether one participated in the contest. This includes, but is not limited to, posting spoilers about the contest and public speculation of the contest.
  • Attempting to exploit bugs in the platform to subvert the constraints of the contest.

Before the contest date, you may wish to check out the tips and help pages.

The contest consists of 5 questions with a range of difficulty from CCC Senior 1 to CCC Senior 5. It is highly recommended to read all of the problems. You will have 3 hours to complete the contest. After the contest window begins, you may begin at any time. Your personal timer will start counting down, and you will be able to submit until 3 hours from when you started, or until the hard deadline, whichever comes first.

After joining the contest, you proceed to the Problems tab to begin. You can also go to Users if you wish to see the rankings.

We have listed below some advice as well as contest strategies:

  • Remove all extra debugging code and/or input prompts from your code before submitting. The judge is strict — your output must match the judge output exactly.
  • Do not pause program execution at the end. The judging process is automated. You should use stdin / stdout to perform input / output, respectively.
  • It is guaranteed that all the problems will be solvable with C++. We do not guarantee that all problems are solvable in C, Java or Python.

At the end of the contest, you may comment below to appeal a judging verdict. In the case of appeals, the decision(s) of our staff is final.


Problem Points AC Rate Users
Mock CCC '20 S1 - War 5p 29.2% 430
Mock CCC '20 S2 - Flipper Redux 7p 25.5% 251
Mock CCC '20 S3 - SAM I Am 10p 12.2% 65
Mock CCC '20 S4 - Valentine's Day Shopping 20p 6.0% 12
Mock CCC '20 S5 - Tree: The Data Structure 1p 8.7% 2


  • -3
    Plasmatic  commented on April 27, 2020, 4:07 a.m.

    Problems S1-S4 are up! However, due to some issues for S5 it will not be going public at the moment.

    Additionally, since S3 and S4 have augmented test data, different versions have been released:

    S3 here

    S4 here

  • 1
    Plasmatic  commented on Feb. 14, 2020, 3:00 a.m. edit 3

    Test data will be augmented before problems are made public. Some solutions that got passing verdicts in contest may not pass on the new data (contest rankings will stay the same however)

  • 4
    c  commented on Feb. 8, 2020, 11:55 p.m.

    Due to an issue with problem 5, the contest has been pushed back by 30 minutes. Sorry for the inconvenience.