We are looking for problems of varying difficulties and types (batch, output-only, or interactive).

To get an idea of style and difficulty, see the problems from the previous years, that is 2021 to 2024 (https://stats.egoi.org/tasks/).

Additionally, the topics and techniques used must conform to the IOI syllabus (https://ioinformatics.org/page/syllabus/12).

Acceptance Criteria

Any problem submitted to EGOI 2025 must consider the following criteria to be considered for acceptance:

• Novel: Similar problems have not been published in recent versions of the competition nor in any other similar competition.
• Engaging: The problem is interesting and the description is formulated in such a way that motivates its resolution.
• Comprehensible: The problem is clear and easy to understand; there is no ambiguity in the description of the task.
• Solvable: The problem is solvable by the EGOI contestants.

We will be pleased to invite the authors of the selected problems to the contest. The authors are responsible for arranging their travel, but the costs for their stay will be covered by EGOI.

Note that we will not be accepting problems from authors who are still attending highschool to avoid potential conflicts of interest.

Submission

A problem submission must contain:

• Author’s contact details (first name, last name, affiliation, and email).
• A problem statement in English together with the description of subtasks along with their expected difficulty.
• Images and additional assets required by the problem statement or its resolution.
• Solution sketches.

As additional recommendations:

• Solution sketches should be provided in C++, Python, or any other major programming language.
• Sample test cases to illustrate the problem.
• The motivation behind the task.
• Additional comments that are relevant to the understanding and resolution of the problem.

Attach all files for one problem in a single ZIP archive and submit it to the SC at sc@egoi2025.de. The SC will confirm the receipt of the submission via email. 10 tasks will be chosen from the submitted ones but only 8 will make it to the competition.

License

The problems accepted in the actual competition will be made available under a Creative Commons Attribution license (CC-BY) after the competition is over. Before that, authors must agree on granting EGOI an exclusive license to use the submitted material until (and including) July 19, 2025.

Additionally, authors warrant that problems, including additional provided material, won't be disclosed to any third party while the exclusive license is still in place.

This means that authors, their collaborators, and any other EGOI member or guest that has access to the accepted problems must not use a problem or any of its variants in any other competition or training until EGOI 2025 has ended.

If authors are involved in national trainings we expect them to not be biased in the way they select topics and problems. In particular, it is ok if authors are involved in the national girls training. Ideally, they discontinue this activities once their problem has been accepted to the competition. If this is not possibly for capacity reasons then it is acceptable to continue to train while taking extra care not to be influenced by the accepted problem.

This is done to guarantee the confidentiality of the problems and provide fair competition.

Deadlines

• Submission deadline: Sunday, 19 January 2025
• Olympiad: Monday, 14 July 2025 — Sunday, 20 July 2025