Practice Contest

The IOI 2017 practice tasks are available below:

The tasks attachments can be downloaded from below:

All tasks are published under the Creative Commons Attribution (CC-BY) License.

Online Submission

You can submit your solutions to our online grading system. The online system is available from June 25 to July 28, 2017. A live scoreboard is also available during this period. The username and password for all contestants are sent to their corresponding team leaders.

The same grading system will be used in the IOI 2017. Therefore, we recommend all contestants to login to the system and have at least one submission in order to see how the system works.

Ask Questions

For questions about the tasks, test data, etc., please use the “Communication” link of the online grading system, or send an email to the host scientific committee: Please note that due to time differences, you may receive answers to your questions with some delay.

In case of any technical issues (the grading system, login information, etc.), please contact the Host Technical Committee by sending an email to

Contest Environment

To get familiar with the IOI 2017 contest environment (including IDEs, editors, compilers, and debuggers), you can download a copy of our contest image from this page.