Problem 56040. A Binary Search

This is a good exercise, but you can't enforce people to do a binary search in a programming competition unless you can find a way to identify a search done with a binary search uniquely.

Maybe requiring that the sequence of midpoints until a key is retrieved is returned as part of the solution. It would make it harder to "cheat".

You can add the incrementation of the number of iterations in your algorithm's description and test its exact value in the test suite.