DMOPC '17 December Contest

Welcome to the third Don Mills Open Programming Competition of the 2017-2018 season!

The problem writers this time are jackyliao123, Kirito and r3mark.

If this is your first time participating in the DMOPC, you can learn about our system here.

This round will be rated for all participants who submit at least once.

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

This contest will consist of 6 main problems, the difficulty of which may range anywhere from CCC Junior to CCO level.

Some problems offer partial marks in the form of subtasks. If you cannot solve a problem fully, we encourage you to go for these partial marks.

You will have 3 hours to complete the contest. After the contest window begins, 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 (noon EST of Dec. 13th), whichever comes first.

Additionally, this contest will feature a 7-th problem (Problem 0) for students who are just getting started with programming.

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:

  • Start from the beginning. Ties will be broken by the sum of times used to solve the problems starting from the beginning of the contest. The last submission time of your highest score will be used.
  • It is not guaranteed that the problems will be in order of increasing difficulty. Reading all of the statements is recommended.
  • 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.
  • It is guaranteed that all the problems will be solvable with C++.

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.


  • 3
    r3mark  commented on Dec. 13, 2017, 9:48 p.m.

    Editorials to all the problems are now up.

  • 6
    Kirito  commented on Dec. 13, 2017, 5:55 p.m.

    As a general response to the requests for editorials: jackyliao123, r3mark, and I are somewhat busy at the moment. As such, editorials may be delayed until the end of the week.

  • 0
    alextxu  commented on Dec. 13, 2017, 5:53 p.m.

    Will there be an editorial for P2?

  • 2
    radoslav11  commented on Dec. 13, 2017, 4:48 p.m.

    When will the editorial to P4 be up?

  • 2
    YiIsMe  commented on Dec. 13, 2017, 2:36 p.m.

    Are you serious? P2 is only 5pp. You really need to rethink your point values.

    • 1
      Roynaruto  commented on Dec. 13, 2017, 2:55 p.m.

      It's actually a lot easier than most of us thought. I felt the same way until someone showed me the way. :'(

  • 1
    rpeng  commented on Dec. 12, 2017, 7:45 p.m.

    Has the window been extended by 12 hours? The email said stopping by midnight.

    • 3
      r3mark  commented on Dec. 12, 2017, 7:48 p.m.

      Yes, it has. The contest now ends at noon EST Dec 13.

      • 1
        rpeng  commented on Dec. 12, 2017, 7:51 p.m.

        1 more question since I'm having trouble digging out the rules: are there systests (CF style), or is it full feedback?

        • 5
          jkguipqnjcy49979693  commented on Dec. 12, 2017, 7:57 p.m.

          Systests for the last 3 problems, full feedback for the rest. No hacks, though.

  • 13
    bradypotter16  commented on Dec. 10, 2017, 8:12 p.m.

    This contest starts at 12 on 12/12!

    • 0
      1419903188  commented on Dec. 13, 2017, 3:15 p.m.

      could be even better if you post this comment right at the beginning of this contest

    • 11
      Kirito  commented on Dec. 12, 2017, 9:38 p.m.

      As of 21:36 EST, that comment also has 12 upvotes!