Finding the common ancestor in a binary tree

Question

This question was asked to me in an interview: I have a binary tree and I have to find the common ancestor (parent) given two random nodes of that tree. I am also given a point

Answer 1

This problem has been very well-studied and there are known algorithms that can solve it in linear time. This paper describes many different approaches you can use to solve it. Admittedtly it is a research paper and so the algorithms are a bit tricky, but some of the approaches it describes are actually quite feasible.