Google Software Engineer interview questions

Contacted by a recruiter online and a phone interview was set up in two weeks. The phone interview includes simple technical questions, such as how to convert a number in decimal to binary. There was no behavior questions asked.

Given a sorted array of n integers that has been rotated an unknown number of times, write code to find an element in the array. Design an algorithm and write code to find the first common ancestor of two nodes in a binary tree. Avoid storing additional nodes in a data structure.