Discord Server

You can join the Discord Server, contact the administrators and join the community here.


CP::OJ also has contest ratings (you are rated on how well you do in a contest!), which are typically applied strictly for public contests. The ratings are as follows.

Ratings Chart
1500-1799Candidate Master

It is important to note that the default rating for all users is 1200.


As the judge supports comments, we would like to remind everybody that comments are typically used to ask for help. Basically, you should consider, before you post a comment, if it will benefit other users in the future.

Problem Setting

Do you want to submit a problem to CP::OJ? Sure! Feel free! But make sure you follow the guidelines:

  • Clear, simple problem statement
  • Test cases are accurate (they follow the proper constraints)
  • Your test cases will include the worst-case scenario
  • Problem statement should include: input and output specifications, sample input and output, problem description, and, if needed, a sample explanation describing the reason for your sample output.
  • Test cases are (preferably) below 10 MB. If you need more, we recommend you to learn how to use a generator.

Keep in mind that the problem statements are generated using Markdown and LaTeX. If you don't know how to use \(\LaTeX\), you can go to hostmath.com to view how they are used.

Any problem that does not follow the above format will simply be rejected, without explaining why, with the exception that it is a reason that is not included here, which will be specified.

While the problems are made by you, we reserve the right to change the point values accordingly.