Site Requirements

Sites must meet three types of requirements:


Operating Systems

One of the following is required: Windows XP/Vista or higher, Mac OS 10.4 or higher, or any *NIX variant that will fully support the compilers specified below.


Sites must provide the following freely-available compilers. These are the same compilers used by the Kattis site, and will ensure that students do not run into situations where code compiles fine on the site, but then doesn’t compile when submitted to the Kattis site.

  • C/C++

    A compiler (and corresponding debugger) supporting C++14 is required.

    We recommend using GNU’s gcc 5.4 or higher plus a compatible version of GNU’s gdb debugger. Windows sites should use the MinGW port. Mac OS 10.4 and higher have a suitable gcc and gdb available as part of the developer tools, which ship with the OS but are not installed by default.

  • Java

    The Java 8 SDK or higher is required (make sure you have the java, javac, and jdb commands). Either the Sun or OpenJDK version is acceptable, but take into account that Kattis uses the OpenJDK compiler. Java 7 can be used if using Java 8 is not possible.

  • Python

    The official Python 2.7 and 3.5 interpreters (as available on must be installed. For Python 2.7, the Pypy interpreter may be used, as that is the one used on Kattis.

If your site includes multiple version of a given compiler, your site-specific documentation must specify how to invoke the correct compiler.

The exact compiler flags are specified in the notes to teams. Although the teams are told to use these commands, you may optionally want to provide command aliases (e.g., icpc-gcc, icpc-javac, etc.) that invoke the correct compiler with all the correct flags.

Integrated Development Environments (IDEs)

GNU’s gcc and Sun’s javac (from the JDK) are command-line compilers, and gdb and jdb are command-line debuggers, so graphical IDEs are not required. It is sufficient to provide one or more good text editors and a command line. Emacs, Vim, and jEdit are powerful editors that support all required languages and work on virtually all operating systems.

However, sites are encouraged to provide IDEs if possible. C/C++ IDEs must work with gcc, and Java IDEs must work with the provided JDK. In addition, IDEs must be freely available so teams can practice with them in advance before the contest. The following IDEs meet these requirements, and are also used in the World Finals:

  • Eclipse 4.7 (Java, C/C++, and Python)
  • IntelliJ (Java)
  • CLion (C/C++)
  • Pycharm Community Edition (Python)
  • Code::Blocks (C/C++ and Java)

Note: IDEs must ideally be configured to use the same compilers and the same compiler flags specified in the notes to teams. If that is not possible, please make sure you inform teams in the site-specific instructions, so they know to test their code with the right flags from the command line.


Computers must support the software required above, and must be configured so that they are all functionally identical. If possible, they should also be physically identical, although it is sufficient to have the same CPU and RAM.

Network Security

We use a central judging system called Kattis, the same system used at the World Finals. With Kattis, there is a single central server that does all the judging. Teams make their submissions via a web interface, so it is important that the machines are configured to access only that web interface, but not the rest of the Internet.

To do this, your site must limit Internet access to just the Kattis site, as well as a regional site where we will post reference documentation.

There are two mechanisms to accomplish this:

  • Using the regional proxy

    We will be running an HTTP proxy for the region that will ensure that teams can only access the Kattis site. On the site, you will only need to limit IP access to that HTTP proxy. The web browsers on the contest machines must also be configured to use this proxy by default (or you must give teams instructions on how to setup the browsers accordingly).

    This is our preferred mechanism for limiting access to Kattis.

  • Running your own proxy

    It is also possible for your site to limit access to Kattis by setting up your own web proxy. However, doing this requires a non-trivial setup. If this option is preferable, please Contact the Director of Systems and we’ll send you more details (we can also share the regional web proxy’s configuration file; we use Squid so, if your site does too, it may make your setup easier).

Network Security

In the weeks before the contest, we will be running a number of dry runs using the exact same configuration we will use during the actual contest. We encourage you to make use of these dry runs to ensure that everything is working correctly on your end. In particular, you should check that:

  • You can access the regional Kattis site but not any other sites (you can test and
  • You cannot access any other hosts on the Internet.
  • You can log into Kattis and submit solutions to problems.
  • You can submit clarifications, and receive responses (someone will be supervising the dry run, and will respond to clarification requests).

Please note that, at any other time, the regional proxy will be left running so you can run tests. However, there will be no one actively monitoring the proxy or the Kattis site if any issues arise.

Physical Configuration

Teams must have a workstation (which may consist of more than one desk) large enough to allow all three team members to work simultaneously, one using the computer while the other two work on paper. Teams must be separated from each other far enough so that team members may talk quietly among themselves without risk of being overheard by nearby teams. Many configurations are possible. Some sites put each team in a classroom by themselves, and at the World Finals all teams are together in a large hall.

If teams do not have a room to themselves, it is desirable to provide one or more additional large common rooms with several large whiteboards or chalkboards where team members may go to discuss ideas.

Regardless of physical configuration, sites must take reasonable steps to ensure that there is no physical communication between a contestant and anyone but his or her team members.