CPC '21 Contest 1

Welcome to the first Competitive Programming Contest (CPC) of 2021!

The problem writers this time are Plasmatic, Tzak, kevinyang, JoshuaL, crackersamdjam, and AQT.

Thanks to Riolku, Zeyu, DM__Oscar, RandomLB, tankibuds, kdrkdr, blin00, arvindr9, and Tony1234 for testing and feedback on problems.

This round will be rated for all participants.


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

This contest will consist of 7 main problems, the difficulty of which may range anywhere from CCC Junior to CCO level. Additionally, this contest will feature a 8-th problem (Problem 0) for students who are just getting started with programming.

You will have 3 hours to complete the contest. After the contest window begins (at 00:00:00 EDT of July 24th), you may begin at any time. Once you enter the contest, 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 (00:00:00 EDT of July 27th), 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.

Here are the parameters of the contest:

  • Some problems offer partial marks in the form of subtasks.
  • The score distribution for the problems will be 30 points for P0, and 100 points for the other problems.
  • Ties will be broken by the sum of submission times on each problem that had the greatest score. If multiple submissions have the greatest score on a problem, the earliest one will be selected.
  • There will be no penalty for wrong submissions.
  • Scoreboard will be hidden, until your window is over. Divulging the contents of the scoreboard to participants who have not finished their window is an offense, the punishments of which are listed below.
  • Problems will be approximately increasing in difficulty, but reading all of the statements is still recommended.
  • Checkers: unless otherwise specified, standard. The contest will follow the standard convention of having all lines terminate in a \n character, with no trailing whitespace.
  • Rated for opening the contest. Being able to read the problems will cause the contest to be rated.
  • It is guaranteed that all the problems will be solvable with C++.

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 very strict — most of the time, it requires your output to match exactly.
  • Do not pause program execution at the end. The judging process is automated. You should use stdin / stdout to perform input / output, respectively.
  • Python users are recommended to try both PyPy 2/3 and Python 2/3 when submitting.

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 Discord and 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, any suspicious behavior during the contest window may result in your rating being impacted negatively. Such behavior includes, but is not limited to:

  • Divulging the contents of the scoreboard to participants who have not finished their window.
  • 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.

Punishments may include performance being unrated or, for more serious infractions, being forcibly ranked at the bottom of the scoreboard.

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


Problems

Problem Points AC Rate Users
CPC '21 Contest 1 P0 - AQT and Alphabet 3 58.7% 203
CPC '21 Contest 1 P1 - AQT and Fractions 5p 13.0% 110
CPC '21 Contest 1 P2 - AQT and Multiset 7p 19.4% 84
CPC '21 Contest 1 P3 - AQT and Circles 10p 9.4% 66
CPC '21 Contest 1 P4 - AQT and Directed Graph 12p 15.2% 60
CPC '21 Contest 1 P5 - AQT and Modern Art 15p 10.8% 21
CPC '21 Contest 1 P6 - AQT's Break Time is Over 20p 6.6% 14
CPC '21 Contest 1 P7 - AQT and Quarantine 20p 18.3% 10

Comments


  • 2
    justin_g_20  commented on July 27, 2021, 2:47 a.m.

    Will editorials be made available?


  • 6
    Viv_CCGS  commented on July 26, 2021, 4:38 a.m.

    Do the points you earn in the contest affect your points on DMOJ?


    • 6
      justin_g_20  commented on July 26, 2021, 6:21 a.m.

      Yes, they do, at the end of the contest. They affect your dmoj points as at the end, they become normal problems and are weighted based upon their difficulty.


  • 9
    Riolku  commented on July 24, 2021, 11:52 p.m.

    The contest has been extended one day.


  • 9
    Kirito  commented on July 24, 2021, 2:15 p.m. edited

    The judges are currently down due to a prolonged power outage. Anyone whose contest window was affected by this can appeal to have their contest participation unrated.

    Edit: judges are back.


  • 5
    Plasmatic  commented on July 23, 2021, 2:52 p.m. edit 2

    The score distribution for the contest will be 30 points for P0, and 100 points for the other problems- a total of 730 points.


  • 10
    DM__Oscar  commented on July 17, 2021, 11:32 a.m.

    AQT tends to show up where you don't expect him.


  • 1
    dchoo333  commented on July 16, 2021, 10:25 p.m.

    Are all problems solvable in Python 3?


    • 7
      crackersamdjam  commented on July 16, 2021, 10:30 p.m.

      Don’t assume anything that wasn’t stated. My answer is “maybe.”


      • 1
        dchoo333  commented on July 17, 2021, 9:06 a.m.

        OK. Thanks


  • -45
    AQT  commented on July 15, 2021, 9:37 a.m.

    This comment is hidden due to too much negative feedback. Click here to view it.


    • 22
      crackersamdjam  commented on July 15, 2021, 9:39 a.m.

      No, AQT is AQT.


      • 13
        piddddgy  commented on July 17, 2021, 2:47 a.m.

        No, AQT is a cutie! <3


        • 8
          X_Ray  commented on July 18, 2021, 1:46 p.m.

          A Cute T.


          • 8
            vishnus  commented on July 20, 2021, 11:32 a.m.

            A cutie


      • -61
        AQT  commented on July 15, 2021, 1:11 p.m. edited

        This comment is hidden due to too much negative feedback. Click here to view it.


        • 37
          bruce  commented on July 26, 2021, 4:17 p.m.

          Obviously, you underestimate how popular AQT is. Maybe you should set your first target -75, like the perfect ccc score.


        • 10
          csDude256  commented on July 25, 2021, 10:53 p.m.

          Since this has reached -30 votes, can we get 2 geo problems on ccc 2022?


          • 6
            Plasmatic  commented on July 26, 2021, 4:35 p.m.

            reach -75 and then ccc is all geo problems


          • -2
            Badmode  commented on July 26, 2021, 2:02 p.m.

            please no


            • 2
              balathegreat999  commented on July 27, 2021, 9:45 a.m.

              at least you will know what to practice