I know how to reverse a binary tree. I just didn&#x27;t know that that&#x27;s what you called it. To me it means &quot;see if this nested object has children at matching positions&quot;.<p>The problem with the question is that it&#x27;s an intellectual circle-jerk. &quot;Do you know what this fancy term is that nobody uses in their day-to-day life?&quot;. &quot;Oh, you don&#x27;t know? Haha, stupid peasant&quot;.<p>Instead of asking these gotcha questions, why not ask something practical that does the same thing? &quot;Given a complex user model with multiple relationships, how can you map the relationships? Or something like that.