Researchers at the University of Tübingen have found via experimentation that crows are capable of understanding the concept of recursion. In their paper published in the journal Science Advances, ...

Crows are notoriously clever — the songbirds can use tools, understand the concept of zero and follow basic analogies. Now, a new study suggests that their grasp of one complex cognitive principle in ...

Recursion can feel like magic until you understand its simple rules: a base case to stop, and a recursive call to repeat. By breaking problems into smaller versions of themselves, recursion makes ...

This is someone else's code which I'm trying to modify to make it not use global variable. I've been pulling my hair though unable to make this work.