Trilogy Innovations Summer Software Intern interview questions

Telephonic Interview was just on the discussion over my projects. Round 1 questions were: Q1. Given an integer array, return the k-th smallest distance among all the pairs. The distance of a pair (A, B) is defined as the absolute difference between A and B. Q2. Find 2 nodes in a BST whose sum is equal to a given number A. (I had to try it in O(h) space).