Recently, by sending it a letter of invitation to the "Russian AI Cup". Never had Affairs with such things, but interested. Don't prompt online resources (that is when 2+ people
are competing , not Codeforces, etc. for solo-algorithms) where you can:
- to write bots in Java
- to choose for the competition to start a low-level bots (for practice), then more complex, etc.
- there is a permanent "ground" (not time-limited)
- there are visualization competition (though text)
- is arena for the competition of games with simple to implement rules (though TIC-TAC-toe, etc.) - for the "pen test"