International Computer Science Competition

Problems

ICSC problems consist of conceptual problems and programming problems. The problem type is indicated by the following symbols:

• Conceptual problem: Requires logical or mathematical reasoning, solveable by hand.
• Programming problem: Requires implementing a solution in code.

You can score five points for each problem. The difficulty rating ranges from one star (easiest) to three stars (most challenging).
We have compiled training material to help you with concepts relevant for the posed prob-ems. You can access them here: icscompetition.org/training.

Your Solution

You must provide a written description of your solution for all problems in the solution sheet you submit (including code). You may submit handwritten or typed solutions. For program- ming problems, please also upload your code files. You may submit your coding solutions in Python (3.9), Java (OpenJDK 11), C (C99), or C++ (GCC 15.1). To ensure your code is evaluated correctly, please use the provided code skeleton: icscompetition.org/en/#qualification.

You might want to look at the example solutions for our training problems so you can see what a clear and well-structured submission might look like: https://icscompetition.org /docs/solutions/2025/example/en/ICSC_example_2025.pdf.

Qualification Round

The Qualification Round features five problems that cover foundational concepts, logic, and introductory algorithms. Some problems require an abstract explanation of the solution, while others involve the writing of code.

Each problem is worth 5 points. To advance, participants must achieve a minimum score of 15 points for the Junior division, 17 points for the Youth division, and 20 points for the Senior division. Participants are encouraged to show their work, express themselves creatively, and produce efficient algorithms. Outstanding submissions receive special recognition.

Pre-Final Round

Qualified participants tackle six more complex problems over four days, some of which build on concepts introduced in the Qualification Round. The problem set includes:

• 2x Foundational Problems (4 pts each)
• 2x Advanced Problems (6 pts each)
• 2x Research Problems (8 pts each, involving reading and engaging with research papers)

The maximum score is 36 points. To advance, participants must achieve at least 16 points for Junior, 20 points for Youth, and 24 points for Senior divisions. To run the competition at a global scale, the registration cost for the Pre-Final Round is 11 EUR. Financial aid is available to waive or reduce these costs.

Final Round

The Final Round is a fast-paced online exam consisting of 20 multiple-choice questions, with 60 seconds allocated for each question. It covers concepts from previous rounds, including theoretical concepts and algorithmic understanding, but does not involve writing code.

Participation requires supervision by a registered teacher or self-recording with both screen and webcam active. Final rankings and prizes are determined based on performance in this round, with tie-breakers using results from previous rounds.