Rules

The TL;DR

Short on time? Here are the most critical things you need to know about participating in SIL 2026!

• You will compete in teams of 3 to 5 students. [New!] Top teams from the Online Contest will be invited to the in-person Final Contest at the NUS School of Computing.
• You and your team will tackle around 25 batch tasks (scored on correctness) and 1 optimisation task (scored on a curve against other teams).
• To promote inclusivity, 25% of our Final Contest invites are reserved for wild card entry (for teams which consist of members from traditionally underrepresented backgrounds).
• You must not use Generative AI (like ChatGPT, Claude, or Gemini) to help you solve the tasks or code. You cannot ask anyone outside your team for help.
• [New!] Every participant must record your screens for the entire duration of the Online Contest. If we request for your screen recording and you cannot produce it, your team may be disqualified.

Schedule

The Singapore Informatics League (SIL) 2026 is split into two stages: the Online Contest and the Final Contest.

• The Online Contest: This takes place on 5 July 2026 from 9:00AM to 1:00PM (SGT).
• [New!] The Final Contest: Selected teams from the Online Contest will be invited to the Final Contest! This will be a full-day, in-person event hosted at the NUS School of Computing on 15 August 2026. Expect free food, merch, and a day of exciting activities!

Eligibility

If you are currently studying in a secondary school or pre-university institution (such as a junior college, polytechnic, Millennia Institute, ITE, or equivalent), you are eligible to participate!

You will compete in teams of 3, 4, or 5 students. Feel free to mix and match: you can team up with friends from different schools and educational levels!

Online Contest

Format

The contest features two types of tasks: batch and optimisation.

Batch Tasks

Batch tasks require you to produce the correct output for a specific, given input test case.

There will be around 25 batch tasks in total, grouped into four difficulty levels (with Level 1 being the easiest and Level 4 being the hardest). You might be able to solve the Level 1 tasks by hand, but the more difficult tasks will require programming,

Refer to our syllabus, sample tasks, and the SIL 2025 task statements and editorial to learn what to expect!

Test Cases and Scoring

Each task consists of multiple test cases, each representing a specific instance of the task. To make a submission, simply enter your output into the box provided below the input. Your submission will be graded automatically.

A correct submission earns your team the full points for that particular test case. However, each incorrect answer will reduce that test case’s value by 1 point (down to a minimum of 1 point), and you will subsequently be able to reattempt the test case. A task is considered “solved” when all its test cases are answered correctly.

Unlocking Tasks

To keep things manageable, your team will have a maximum of 4 tasks visible at any given time. When a task is solved or skipped, you get to unlock a new one! You will choose from 4 different unlock options, each showing the task’s title, difficulty level, and total points.

Skipping Tasks

Stuck on a tricky problem? Your team is allowed to skip tasks without penalty. Skipping is limited to only once every 20 minutes, so use this option wisely. Once a task is skipped, its test cases become inaccessible and their points cannot be obtained later on.

Hints

Hints will be provided for certain test cases, intended to help point your team towards the right direction. The hint for a test case will be automatically unlocked after your first submission to that test case, no matter if your answer is right or wrong. Once a hint is unlocked, it will remain visible thereafter.

Optimisation Task

We will release 1 optimisation task right at the start of the contest. Unlike the Batch Tasks, this is typically an “NP-hard” problem, where there is no known fast, exact solution! Instead of looking for a binary “right or wrong” answer, your team’s objective is to produce the best possible solution you can.

Test Cases and Scoring

The optimisation task will also consist of multiple test cases, but the scoring works differently:

• First, your output is judged on its quality based on task-specific criteria. This gives you a “raw score”. We will always use your team’s best-scoring submission for each test case.
• Next, your raw score is compared directly against other teams. The team with the best raw score gets full points, while the team with the lowest raw score gets zero points. This gives you a “normalised score”. The exact formula used for calculating the normalised score will be written in the task statement.
• We add up all the normalised scores across the test cases to get your final score for the optimisation task.

A handy “visualiser” tool will be provided alongside the optimisation task. The visualiser displays your output in context of the task and tells you the raw score of your output. Please ensure that you test the output on the visualiser before submitting, as outputs in the wrong format cannot be graded and will not score any points.

Refer to last year’s optimisation task “Wandering Robot” to get a better idea of the format.

[New!] Final Contest

Format

The contest features two types of tasks: batch and optimisation. There will be 10 batch tasks and 1 optimisation task. The scoring for each task is as the same as that of the Online Contest.

Importantly, teams will only use two laptops, to be shared among all members of the team. Teams must use the devices provided, and cannot bring their own.

Batch Tasks

All tasks will be publicly accessible at the start of the contest, and will be ordered arbitrarily. Levels for each task will be hidden.

Hints

Hints will not be provided for tasks in the Final Contest.

Scoreboard

During the Contest

Keep an eye on the scoreboard! A live scoreboard will be publicly accessible throughout the contest, but it won’t show everything. The scoreboard will only reflect points scored by teams on batch tasks. However, you will be able to see the next best raw score for each test case of the optimisation task to help you gauge your standing.

In the last 30 minutes, the scoreboard will be frozen and no longer updated. Points obtained then will still count towards your final score but will not be reflected on the scoreboard.

After the Contest

Shortly after the end of the contest, the full, unfrozen scoreboard will be released. Your team’s final score is given by the sum of your total batch task score and your total normalised optimisation task score. Teams will then be ranked in descending order of final score.

Note that this scoreboard only indicates preliminary results. The scores and ranks of teams may shift while we review and finalise the contest results.

Qualification to Final Contest

Based on the results of the Online Contest, we will invite 32 teams to join us in person for the Final Contest at the NUS School of Computing!

To promote accessibility and inclusivity, a core part of the SIL mission, we have designated 25% (rounded up) of these invites as wild card slots. The remaining 75% are standard slots.

We will go down the final scoreboard of the Online Contest, starting from rank 1. When we look at a particular team:

• If there is a standard slot available, that team is invited.
• If the standard slots are full, but that team is wild card-eligible and there are still wild card slots left, that team is invited!
• Otherwise, that team will not be invited.
• If multiple teams are tied for the last available slot, the tie will be broken in favour of the team whose last score-improving submission came earliest.
  • That is, for each tied team, we consider the timestamp of their last submission that increased their total score; the team with the earlier timestamp receives the invite.

Your team is eligible for a wild card slot if you meet at least one of the following criteria:

• Every member of your team is female or non-binary.
• Every member of your team is from a school that has not yet been represented by any of the teams who have already received an invite.

We implemented wild card entry to support participants from underrepresented backgrounds. If there is a dispute about a team’s wild card eligibility (notably, if we suspect an intentional attempt to exploit the rules), the organisers reserve the right to make the final decision.

Teams attending the Final Contest must ensure that at least 3 of their members are available.

If a team declines their invitation, here is how the empty slot will be filled:

• If a standard slot opens up, the next highest-ranked team will receive the invitation.
• If a wild card slot opens up, this slot will go to the next highest-ranked team on the scoreboard that is wild card-eligible.

Awards

Gold, Silver, and Bronze medals will be given to top teams! Medal boundaries are allocated by the following rules:

• The score necessary to achieve a bronze medal is the largest score such that at least 60% of all teams receive a medal. The bronze medal boundary is calculated solely using scores from the Online Contest.
• The score necessary to achieve a silver medal is the largest score such that at least 30% of all teams receive a gold or silver medal. The silver medal boundary is also calculated solely using scores from the Online Contest.
• The score necessary to achieve a gold medal is the largest score such that at least 50% of all teams in the Final Contest only receive a gold medal. The gold medal boundary is calculated solely using scores from the Final Contest. Teams who qualified for the final contest and did not place in the top 50% will attain a medal corresponding to their performance in the Online Contest.
  • In other words, to earn a gold medal, your team must qualify to the Final Contest and then place in the top 50% in the Final Contest.

Teams that were inactive during the contest or disqualified will not be considered when determining the medal boundaries. In addition, the top 3 teams overall will receive special prizes, presented during the Closing Ceremony of the Final Contest.

Even if your team does not win a medal, every team that competes (excluding inactive or disqualified teams) will receive an official Certificate of Participation. Teams attending the Final Contest can also expect to receive SIL-exclusive merchandise!

Regulations

We want SIL to be a fun and fair experience for everyone. To ensure a level playing field, all participating teams must strictly adhere to the following rules:

• The use of Generative Artificial Intelligence is strictly prohibited. This includes, but is not limited to, tools like ChatGPT, GPT-4o, Claude, Gemini, Deepseek, GitHub Copilot, and Meta Llama. The rule applies regardless of whether the AI is cloud-based, self-hosted, or running locally on your device.
• You may not seek assistance from anyone outside of your registered team members. This means no asking seniors, tutors, or teachers for help, and no posting questions on forums like StackOverflow during the contest.
• You are free to use any existing hardcopy or softcopy references. For example, searching and reading existing threads on StackOverflow or Codeforces is fine, but posting new questions is a violation of the rules.
• Any attempts to hack, sabotage, or otherwise compromise the infrastructure of the contest platform are strictly forbidden.

We know that standard search engines now automatically put AI summaries at the top of your results. Reading these AI-generated overviews when searching for general programming concepts, documentation, or basic syntax (e.g. “how to reverse an array in Python”) is perfectly fine. However, you cannot actively use AI to do the heavy lifting: no pasting contest tasks, test cases, or your own code into any search bar, Large Language Model, or AI coding assistant to ask for help.

You must disable all AI-powered code completion tools (like GitHub Copilot) before the contest begins, if you prefer to use modern IDEs that typically have such features enabled by default.

[New!] Screen Recording

In the Online Contest, all participants must record the screens of all devices used for the entire duration of the contest. You are free to use any screen recording software of your choice. If you are unsure of where to start, we highly recommend reading our Screen Recording Guide for detailed instructions on setting up OBS. If you continue to face difficulties in recording, please reach out to us as soon as possible! Our team will attempt to help you troubleshoot as far as we can. We are contactable through our Discord server or via email at contact@sginfoleague.org.

Once the contest ends, do not delete your recordings! You must hold onto them for at least one month from the end of the Online Contest. To verify results, we may ask to review your team’s screen recordings. If requested, you must submit the screen recordings of all members within three days. Failure to do so may be treated as evidence of dishonest behaviour, which could lead to disqualification.

We understand that technical issues may cause recordings to be lost or corrupted. If this happens to you (either during or right after the contest), please contact us through our Discord server or via email at contact@sginfoleague.org immediately. Do not wait until we ask for your recordings! We will still require you to submit whatever footage you managed to capture, and may also ask for alternative proofs of work, such as your browser history for the duration of the contest. If we cannot confidently verify that you encountered a genuine technical failure, we reserve the right to make the final decision.

Anti-cheating Measures

We take the integrity of SIL very seriously. During and after the contest, we will audit the activity of all teams for anomalies. If we suspect a breach of the rules, we may ask your team to submit proofs of work (full screen recordings, code, and scratch paper used for solving tasks). In some cases, we might also require your team to schedule an interview with us to address our concerns.

If we ask for your proof of work and you cannot provide it, it may be treated as evidence of dishonest behaviour. We reserve the right to impose penalties at our sole discretion, including disqualification without providing a reason.

In serious cases, we may take further action, including banning involved team members from participating in future iterations of SIL or having the matter reported to your school.

Appeals

We will make every effort to ensure that the tasks and test cases are correct. However, you may submit appeals if you spot an issue with the tasks or solutions by emailing us at appeal@sginfoleague.org. Appeals will be processed before results are finalised, and scores will be updated accordingly if an appeal is accepted.

Final Remarks

By registering for SIL, you and your team agree to play by the rules outlined above. If you have any lingering questions, be sure to check out our FAQ. For further clarification, open a Ticket in our official Discord server or drop us an email at contact@sginfoleague.org.