1. Eligibility

The list of countries allowed to participate is closed. These are (in alphabetical order) Belgium, France, Great Britain, Ireland, Italy, Luxembourg, Netherlands, Portugal, Spain and Switzerland.

Each country can be represented by up to six contestants.

Contestants are chosen by their national olympiad’s organizers.

Contestants must be eligible to participate in IOI that same year.

2. Invitation format

Contestants, team leaders, deputy leaders and guests will be invited by the host to participate on site. Accepting this invitation is optional.

Participation with full rights is allowed regardless of accepting or refusing the host’s invitation.

No fees are charged to participants.

2.1. Onsite participation

Teams accepting the host’s invitation will have to book their own transportation, food, accommodation, and bring at least one laptop per contestant to use to participate in the contest.

At least one team organizer must travel with the contestants and accompany them during the whole length of the event.

2.2. Online participation

Teams refusing the invitation who want to participate in the contest will be allowed to do so online.

The team leader will be responsible for the contestants’ proctoring. The team leader can delegate the proctoring to someone else, but ultimate responsibility will remain on the team leader.

2.3. Mixed participation

Teams can partially accept the invitation by having some contestants participate onsite and some contestants participate online. For each, rules 2.1 and 2.2 will apply.

3. Competition format

The contest will take place during one single day.

The contest will consist of four tasks.

Accepted programming languages are only C++.

The official and only accepted natural language is English.

The contest will last four hours and take place on a Contest Management System (CMS) platform. However, this may vary from one edition to another.

Participation is individual.

Each contestant can submit solutions several times for each task.

3.1. Environment

To ensure equal opportunities to all contestants, it is mandatory to participate through the official contest’s virtual machine. During the contest contestants are not allowed to leave the virtual machine to regain control over the host operating system.

No previous code is allowed to be available in the virtual machine before the beginning of the contest.

Programmable keyboards and other devices which may provide pre-written code or hints are not allowed during the contest.

Only one monitor or display is allowed per contestant.

Internet access is forbidden during the contest, except to access the contest platform, an online translator and, if it were the case, the proctoring platform.

Contestants are not allowed to talk or interact with other people or devices during the contest, the proctors being the only exception.

Contestants are allowed to have regular pens or pencils along with blank sheets of paper to use during the contest. These material cannot be shared or displayed to other contestants.

Contestants may have food and drinks during the contest.

3.1.1. Disqualification

Failure to follow the rules will mean the immediate disqualification of the contestant.

If the rules are broken by initiative of the team leader, deputy leader, guest or team proctor, the whole team will be disqualified.

Contestants or teams with unacceptable behaviour or repetitive failure to comply with the rules might be banned from participating in future contests.

3.2. Types of tasks

The tasks are designed to be solved through computer programming algorithms.

The contestant’s solution for each task will consist of a single source code file.

Tasks may be of two kinds:

  • Batch – The contestant’s code is expected to obtain data as input, process it and output the solution.
  • Interactive – The contestant’s code will interact with a grader by asking successive questions and for each question receiving an answer from the grader.

3.3. Feedback

Contestants will receive feedback for each task submission:

  • Accepted (AC): The submitted code is a valid solution for the task.
  • Runtime Error (RE): The submitted code produced a program that crashed during its evaluation.
  • Time Limit Exceeded (TLE): The code produced a program that took too longs to run in at least one of the evaluation tests.
  • Wrong Answer (WA): The code produced a program that, at least for one of the evaluation tests, did not produce the right answer for the data that was provided to it.

Contestants may ask additional questions through the CMS platform or directly to the proctors. Questions need to be phrased to take a “yes” or a “no” for an answer. Questions may be clarification requests about tasks or other non-task related reasons (computer problem, restroom request, food request, etc) but may not be request hints about the tasks or programming.

During the contest announcements may be done by the contest organizers through the CMS platform. It is up to the contestant to notice and read the announcement.

3.4. Grading

Each fully solved task will grant 100 points to the contestant.

There is no penalization for submitting wrong answers.

3.4.1. Subtasks

Tasks may or may not have subtasks. Subtasks grant less than 100 points.

For each task, the maximum grade obtained on each subtask will be added up.

For each task the maximum grade that can be obtained by adding up the grades of the substasks is 100.

3.4.2. Appeals

Appeals can be made during the contest or after the contest up to immediately before the closing ceremony or awards ceremony.

At any time during appeals all contestants’ tasks submissions may be re-evaluated. If it were necessary, re-evaluations may be done to submissions that have not been appealed. Re-evaluations may bring the submission’s grade up or down.

If it were necessary, extra time may be granted to all or some of the contestants, to compensate for technical or judging mishaps during the contest.

3.5. Scoreboard

For each contestant the grade obtained on each tasks is summed to obtain the contestant’s total score in the contest.

Two contestants with the same score are considered equal in the scoreboard, there is no disambiguation procedure.

The scoreboard will not be available during the contest.

3.5.1. Awards

Contestants are awarded with medals, which might or might not be physical.

Medals are allocated following the IOI regulations.

No honorable mentions are contemplated.

3.6. Syllabus

The syllabus of the competition will be the IOI syllabus of the same year.