Tests for Olympiad problems in programming?

Question

Programming

I solve olympiad problems just for fun, at the same time I improve mathematics and algorithms. I ran into a terrible problem in my opinion - after checking in all systems, they do not let me see the tests on which I failed. Downloading a ready-made answer is somehow unsportsmanlike, and you won’t always find answers. And it’s not very good to write tests yourself when you use it for fun and you don’t always see a specific variation of the test.
Question: is there such a checking system in which tests are given? or at worst a solution?

Answer 1

You here -> CLICK!