Watch Karel recursively traverse a (binary) apple tree!

Recursion is an advanced programming technique that is known to lead to elegant programs, but whose usefulness is sometimes questionable because most recursive programs can be rewritten easily in a non-recursive manner. The one example where the efficiency of recursion really stands out is traversing binary trees. Therefore we prepared a short video that shows a relatively simple recursive program for Karel the Robot, that uses recursion to traverse an arbitrary binary tree of apples. Enjoy!