I apologize for the curve title.
Have been once ran into a website where there are a bunch of tasks on programming in pascal/c, the described input and output format. The essence of the service was to test the correctness of the written program. I understand that this is some kind of test-system and it is connected with the Olympiad programming.
But to Google something and could not.
Do not tell me the sites? Interested in language in the first place.