Problem repository of OSN 2025 (also known internationally as TOKI Indonesian NOI Open Contest 2025).
| Alias | Slug | Title (id) | Title (en) | Type |
|---|---|---|---|---|
| SF-A | osn-2025-semifinal-gulali |
Gulali 17-an | - | Batch |
| SF-B | osn-2025-semifinal-juragan |
Juragan Bebek | - | Batch |
| SF-C | osn-2025-semifinal-spiral |
Kebun Apel | - | Batch (w/ partial scoring) |
| Alias | Slug | Title (id) | Title (en) | Type |
|---|---|---|---|---|
| 0A | osn-2025-balik |
Bebek Pak Dengklek dan Bu Dengklek | - | Batch |
| 0B | osn-2025-lcmxor |
Pasangan Malang | - | Batch |
| 0C | osn-2025-batu |
Es Batu | - | Interactive |
| 1A | osn-2025-hujan |
Taman Hujan | Rain Park | Batch |
| 1B | osn-2025-tarik |
Larik Tarik | Twist List | Batch |
| 1C | osn-2025-mikroba |
Mikroba Brantas | Brantas Microbes | Interactive |
| 2A | osn-2025-kpk |
Festival KPK | LCM Festival | Batch |
| 2B | osn-2025-resonansi |
Pertahanan Malang | Malang Defense | Batch |
| 2C | osn-2025-xor |
Tukar XOR | XOR Exchange | Batch |
| Alias | Slug | Problem Author(s) | Developer(s) |
|---|---|---|---|
| SF-A | osn-2025-semifinal-gulali |
Mushthofa | Mushthofa |
| SF-B | osn-2025-semifinal-juragan |
Ashar Fuadi | Ashar Fuadi |
| SF-C | osn-2025-semifinal-spiral |
Ammar Fathin Sabili | Ammar Fathin Sabili |
| Alias | Slug | Problem Author(s) | Developer(s) |
|---|---|---|---|
| 0A | osn-2025-balik |
Ammar Fathin Sabili | Ammar Fathin Sabili |
| 0B | osn-2025-lcmxor |
Prabowo Djonatan | Prabowo Djonatan |
| 0C | osn-2025-batu |
Ammar Fathin Sabili | Prabowo Djonatan |
| 1A | osn-2025-hujan |
Maximilliano Utomo Quok | Maximilliano Utomo Quok |
| 1B | osn-2025-tarik |
Prabowo Djonatan | Alfonsus Raditya Arsadjaja |
| 1C | osn-2025-mikroba |
Ammar Fathin Sabili | Ammar Fathin Sabili |
| 2A | osn-2025-kpk |
Andrew | Andrew |
| 2B | osn-2025-resonansi |
Maximilliano Utomo Quok | Maximilliano Utomo Quok |
| 2C | osn-2025-xor |
Prabowo Djonatan | Prabowo Djonatan |
Ashar Fuadi and Joel Gunawan also developed unpublished (backup) problems.
The problem statements and upsolving are available on TLX: Semifinal / Final.
The editorial may also be found on the same link.
Each problem contains a problem directory root.
A problem directory root may contain the following files and directories:
- ID problem description (
description-id.html) - EN problem description (
description-en.html) - Model solution (
solution.cpp) - Test case generator (
spec.cpp) - Subtasks solution (
solution-<subtask-number>.cpp) - Alternative solutions (
solution-<author>-<verdict>-<solution-name>.cpp) - Render directory (
render/) - Helper directory (
helper/) - Communicator (
communicator.cpp) - Output validator (
scorer.cpp)
Problem description in Bahasa Indonesia. The HTML file uses Katex syntax to render the math equations. There is a description header file in utils/ to render the preview.
Problem description in the English language.
The solution used to generate the test cases.
Test case generator using tcframe 1.8.0.
Solutions that are used to test the subtasks.
Several alternative and incorrect solutions for testing.
The assets (usually images) that are used by the HTML description file.
Scripts that may help with problem preparation or the raw files of the assets in render/.
For communication in interactive problems, using tcframe format.
To validate solutions that do not use exact match as well as to allow partial scoring, using tcframe format.
All tasks and materials are published under the Creative Commons Attribution (CC-BY) License.