So had my phone interview yesterday.
He asked me three questions. I answered all of them with the optimized complexity. Waiting for the answer.
Questions #2:
Given a binary tree find the longest path from any node to another node. -> used recursion to solve it. Don't know if this question exists here on leetcode.
Question #3:
given an array find one of the local minimas in the arr. ex: [5 7 8 6 5 6] -> should return index 1 or 4.

Hope this helps for people who are prepping...