You have 30 seconds to invert a binary tree. Go.
>>51430394(define (invert-tree tree)
(if (empty-tree? tree)
(make-tree (invert-tree (right-branch tree))
(invert-tree (left-branch tree)))))
Assuming binary trees are implemented, that is.
>he just didn't understand a question
I think this is the case. "Inverting a binary tree" is vague as fuck. It sounds like they want the tree turned upside-down or restructured in another way. Not just a simple left-right swap of every node's children.
Maybe that's what they were intending. To see if he would ask qualifying questions.