Key Details
The Singapore Informatics League (SIL) 2025 will be held online on 29 November 2025, from 9am to 1pm (SGT).
Eligibility
All students currently studying in secondary schools or pre-university institutions (junior colleges, polytechnics, Millennia Institute, ITE, or equivalent) are eligible to participate. Students will compete in teams of 3, 4, or 5. Team members may be from different schools and educational levels.
The contest features two types of tasks: batch and optimisation.
Batch Tasks
Overview
Batch tasks require students to produce a correct output for a given input test case. Easier tasks may be solvable by hand; harder ones will require programming. The contest will have about 30 batch tasks.
Tasks are grouped into levels 1 through 4, with 1 being the easiest and 4 being the hardest. Refer to the syllabus and our sample tasks for more detailed information.
Test Cases and Scoring
Each task consists of multiple test cases, each representing a specific instance of the task. To make a submission, enter your output into the box provided below the input. Your submission will be graded automatically.
A correct submission awards the full points for that particular test case. However, each incorrect answer will reduce the test case’s value by 1 point (down to a minimum of 1), and teams will subsequently be able to reattempt the test case. A task is considered solved when all its test cases are answered correctly.
Unlocking Tasks
At any time, at most 4 tasks will be visible to teams. When a task is solved or skipped, teams may unlock a new one. Teams will choose from 4 unlock options, each showing the task’s title, difficulty level, and total points.
Skipping Tasks
Teams are allowed to skip tasks without penalty. However, skipping is limited to once every 20 minutes. Once a task is skipped, its test cases become inaccessible and their points cannot be obtained.
Optimisation Task
Overview
There will be one optimisation task, released at the start of the contest. It will typically be an NP-Hard task, where no efficient exact solution exists. Teams should aim to produce the best possible solution. Outputs will be scored based on quality, not binary correctness, according to task-specific criteria. A team’s highest scoring submission will determine its final score for the optimisation task.
A visualiser will be provided along with the optimisation task. The visualiser displays your output in context of the task and gives the raw score of your output. The visualiser’s score is designed to closely approximate the final score, but minor differences may occur. 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.
Scoreboard
During the contest, a scoreboard with the total scores of teams will be publicly accessible. This scoreboard will update periodically. The scoreboard will only reflect points scored by teams on batch tasks (and not the optimisation task). In the last 30 minutes, the scoreboard will be frozen and no longer updated. Points obtained then will still count towards a team’s final score but will not be reflected on the scoreboard.
Gold, Silver, and Bronze awards will be given to top teams. Award boundaries are allocated by the following rules: The score necessary to achieve a gold medal is the largest score such that at least one twelfth of all contestants receive a gold medal; The score necessary to achieve a silver medal is the largest score such that at least one quarter of all contestants receive a gold or silver medal; The score necessary to achieve a bronze medal is the largest score such that at least one half of all contestants receive a medal;
Regulations
Teams are strictly prohibited from using Generative Artificial Intelligence. This includes but is not limited to tools such as ChatGPT, GPT-4o, Deepseek, Copilot, Gemini, Meta Llama LLMs, etc., regardless of whether they are cloud-based, self-hosted, or on-device.
Teams must not seek assistance from others not within the team, including from seniors, tutors, or posting to StackOverflow.
Teams must not attempt to compromise the infrastructure of the contest platform.
Teams may use any existing hardcopy or softcopy reference. For example, searching on StackOverflow is allowed, but posting to StackOverflow is not.
Anti-cheating Measures
During and after the contest, the organisers will audit the contest performances of all teams for anomalies. If organisers deem teams to have breached the rules, we reserve the right to impose penalties including disqualifying teams without assigning a reason.
Teams are required to retain their code and/or scratch paper used for solving tasks, especially for level 3 and 4 tasks. These proofs of work could aid in dispelling any cheating suspicions levied upon teams. The organisers may request for these proofs of work if a team is suspected of breaching the rules.
In serious cases, the organisers may take action including but not limited to banning team members from participating in future iterations of the SIL or having the matter referred to their respective schools.
Appeals
The organisers will make every effort to ensure that the tasks are correct. However, teams may submit appeals if they find issues with the problems or solutions by emailing [email protected]. Appeals will be processed before final results are released, and scores will be updated accordingly if an appeal is accepted.
Final Remarks
By registering for SIL, all participants agree to abide by the rules outlined above. Teams with questions should refer to the FAQ. For further clarification, contact the organisers at [email protected].
