Amazon Sr. Software Engineer interview questions

Phone interview: 1) What data structure would you use to represent building and doors 2) How would you find shortest path from any room to exit? Virtual onsite interview: 1) Implement Unix find utility as a library API - Inputs: Starting folder and user defined criteria to match lets start with a) name pattern and b) max size threshold - Output: List of files matching the given criteria - Looking for design of abstractions (inputs), implementation of the API itself and sample usage 2) Given a list of strings, determine if they are isomorphic and group them by isomorphism. Two strings X and Y are called isomorphic if all occurrences of each character in X can be replaced with another character to get Y and vice-versa. Consider the strings “ACAB” and “XCXY”. They are isomorphic as we can map ‘A’ -> ‘X’, ‘B’ -> ‘Y’ and ‘C’ → ‘C’. Mapping from a character to itself is allowed but two different characters may not be replaced by the same character. 3) Find the Balance point of an Array // [3, -2, 0, 4, 6, -5] -> [3] 4) behavioral questions (actual interviewer didn't show up) 5) Mobile System Design