Can you recommend good Olympiad problems?

Question

Programming

There are 3-year students who need to be trained in programming. In particular, in algorithms and data structures.
For this we need olympiad tasks. But Timus, the infection, is big, and there are a hell of a lot of tasks there, even your eyes run wide.
Can you advise on those tasks that you personally like?

Answer 1

Not Olympiad, but interesting - Project Euler.