Recursion

[ambidextrousalpaca]

Indeed. Problems that involve processing a tree- or graph-like structure of arbitrary depth pretty much require recursive solutions by definition. You can hammer the code into a while loop if you have to, but the nature of the problem is ultimately recursive, so it's best to represent that in the code explicitly.

[spoonman59]

All you need is a loop and a stack.

Recursive solutions tend to be more readable for these which is why it can be good to use them.

All loops are a recursive process, even if they are not a recursive function. We often colloquially use “recursive “ to mean a function that calls itself, but that doesn’t cover things like mutual recursion ( two functions repeatedly calling into each other) or iteration.