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Contester

Competitive programming judge

About Contester

Contester is a place to solve programming problems and see how each submission performs against the problem's tests.

How to use Contester

  1. 1. Browse problems

    Open the problem archive and choose a statement to work on.

  2. 2. Access your account

    Sign up for an account, or sign in if you already have one.

  3. 3. Write and submit

    Choose a supported language, write your solution in the editor, and submit it for judging.

  4. 4. Follow the result

    Watch the verdict update live, then review the time, memory, and verdict reported for each test.

How judging works

Contester uses isolate to compile and run submissions in a fresh sandbox box for each execution. CPU, memory, process, and output limits are applied, and the program receives a private network namespace.

System runtime paths are mounted read-only, while the sandbox's /box working directory is writable for the run. Time-limit verdicts use measured CPU time; a separate wall-clock limit stops programs that are stuck without consuming their CPU budget.

Project

The code and development history are available on GitHub.

Source repository