DMOPC '20 January Contest

Welcome to the third DMOJ Monthly Open Programming Competition of the 2020-2021 season!

The problem writers this time are Kirito, Riolku, nthistle, AvaLovelace, and rpeng.

Please note that this contest will be full feedback.

Please note that this contest will have a different tiebreaking scheme from earlier contests. (See below for details.)

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 5 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 (00:00:00 EST of February 1st), 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:

  • Ties will be broken by the maximum time of your best submissions. If two submissions on a problem share the same max score, the earlier submission is taken.
  • 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++.

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:

  • 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 Editorials
DMOPC '20 Contest 3 P1 - Present Checking 5p 50.0% 429 Editorial
DMOPC '20 Contest 3 P2 - Bob and Parallel-Ks 7p 13.1% 160 Editorial
DMOPC '20 Contest 3 P3 - A Ring of Buckets 12p 7.0% 60 Editorial
DMOPC '20 Contest 3 P4 - Bob and Typography 15p 2.5% 9 Editorial
DMOPC '20 Contest 3 P5 - Tower of Power 25p 6.8% 60 Editorial

Comments


  • 2
    Kirito  commented on Feb. 8, 2021, 5:26 a.m. ← edit 2

    Ratings for DMOPC have been finalized. If you wish to dispute your rating, please email us at contact -at- dmoj -dot- ca, or message us on the DMOJ Discord.


  • -8
    qwertyqwertyqwerty123  commented on Feb. 2, 2021, 6:53 a.m. ← edited

    This comment is hidden due to too much negative feedback. Show it anyway.


    • 3
      Aaeria  commented on Feb. 5, 2021, 6:30 a.m. ← edit 2

      P2 Solution: https://github.com/stevenbai0724/DMOJ-Solutions/blob/8418aa9b5fefedc4a95201952097b97397ad628e/DMOPC/dmopc20c3p2.cpp


    • 15
      verybadallen  commented on Feb. 2, 2021, 3:13 p.m.

      It would be great if I just instantly got AC on the problem after clicking on the editorial. Then I wouldn't have to actually think about how to solve the problem (who even does that anyways lmao) and get my free pp 🤑


      • -5
        qwertyqwertyqwerty123  commented on Feb. 2, 2021, 7:32 p.m.

        This comment is hidden due to too much negative feedback. Show it anyway.


      • 2
        qwertyqwertyqwerty123  commented on Feb. 2, 2021, 7:30 p.m.

        what is this approach ? i don't get , aren't you tryin to understand just what i am saying or just saying what just came in mind . if someone for example : doens't understand how to implement some sliding window technique , how should he understand the editorial ( i mean he has never seen such technique before with that topic ) . if you just solve problems for counting how big your solved problems are , then what's purpose of even editorials .


  • 5
    andrew_l  commented on Feb. 1, 2021, 6:41 p.m.

    If I want to appeal should I post my actual appeal here or contact someone?


    • 6
      maxcruickshanks  commented on Feb. 1, 2021, 6:50 p.m. ← edit 3

      I think the best and fastest way to appeal a decision would be to join the DMOJ Discord and ask a staff member. You could also send an email to contact@dmoj.ca.


      • 4
        andrew_l  commented on Feb. 1, 2021, 6:56 p.m.

        Thank you!


        • 7
          DM__Oscar  commented on Feb. 1, 2021, 9:23 p.m.

          Congrats on the successful appeal!


          • 7
            andrew_l  commented on Feb. 1, 2021, 10:06 p.m.

            thanks for your help!!


  • 5
    Ausmosian  commented on Feb. 1, 2021, 12:31 p.m.

    I am new here guys, can anyone please tell me how can I view others submissions after the contest is over, and after how much time are the editorials published usually ? Thanks :)


    • 7
      wleung_bvg  commented on Feb. 1, 2021, 6:34 p.m. ← edited

      You should be able to view submissions when the problems are made public AND after you have solved the problem yourself. This usually happens within a few hours after the end of the contest, but sometimes it can take a little longer.

      Editorials are supposed to be published around the same time, but it also depends on whether the author wants to write one (doesn't always happen). For this DMOPC, there appear to be drafts for P2, P4, and P5 editorials, with P1 and P3 editorials reportedly being completed soon.


    • 2
      kartikey30  commented on Feb. 1, 2021, 2:26 p.m.

      Bro, I think you cannot see the solutions. Although I am also new, from which college due you study, we should meet!


  • 9
    Kirito  commented on Feb. 1, 2021, 6:50 a.m.

    Preliminary ratings are out. This post will be updated once ratings are finalized.


  • 6
    Plasmatic  commented on Jan. 31, 2021, 9:44 p.m.

    1 point under cco cutoff


  • 17
    medmoj  commented on Jan. 29, 2021, 1:12 a.m.

    Wow, 4 contests upcoming at the same time...


  • 4
    samliu12  commented on Jan. 29, 2021, 12:53 a.m.

    Ties will be broken by the maximum time of your best submissions.

    Does this mean that submissions that earn you no points won't increase your time?


    • 4
      maxcruickshanks  commented on Jan. 29, 2021, 3:19 a.m.

      Yes: If two submissions on a problerm share the same max score, the earlier submission is taken.


      • 3
        samliu12  commented on Jan. 29, 2021, 3:26 a.m.

        Thanks. By the way, I noticed the contest said '20, not sure if that's intentional.


        • 21
          wleung_bvg  commented on Jan. 29, 2021, 3:40 a.m.

          Every year, someone complains. The year in the contest name refers to the school year (2020-2021).

          Of course this issue could be avoided if one were to name their contest in numerical order. For example, Wesley's Anger Contest 1, Wesley's Anger Contest 2, and so on ...


          • 14
            Kirito  commented on Jan. 29, 2021, 3:55 a.m.

            Pop quiz: which contest number is DMOPC on? (No cheating by looking it up.)


            • 8
              dxke02  commented on Jan. 29, 2021, 12:49 p.m.

              Around 27-31 or something


              • 13
                Kirito  commented on Jan. 29, 2021, 5:05 p.m.

                WA


                • 8
                  dxke02  commented on Jan. 29, 2021, 6:26 p.m.

                  is it 38-41?


                  • 18
                    BattleMage_  commented on Jan. 30, 2021, 7:34 p.m.

                    TLE


                    • 1
                      Bobbychuck12  commented on April 3, 2021, 2:21 p.m.

                      If only I could make my answer faster by taking away the obvious loops in it


  • 19
    sortSlave  commented on Jan. 29, 2021, 12:51 a.m.

    A contest in the proper month?!?