IOI 2019 will take place in Azerbaijan, from August 4-11, 2019. More info is available on the official website.
Coming soon IOI 2019 in Azerbaijan
Croatian Open Competition in Informatics
The fourth contest will be held on Saturday, 16th December 2017, starting at 14:00 (GMT/UTC). Check out your local times at http://hsin.hr/coci/next_contest.html.
You may use Python, Pascal, C, C++ or Java as your programming language of choice.