Apptio Senior Software Engineer interview questions

Extremely poor, interviewer gave a coding question and specified it should be solved in O(n) time and O(n) space complexity within 10 mints with code. Even after clarifying that O(n) space means i can use extra space of O(n), he confirmed on that. Given scenarios i was figuring solution in that direction only by using extra space ,that too on shared screen with vocally explaining him the approach. At end of 10 mints he says u cannot use extra space, and kept bugging me with time, that u have 5 more mints write code , even though i was not done with dry run of approach. Within 15 mints he had annoyed me so much that i only lost interest in the opportunity and asked him to end interview. Cause if interviewer himself is not knowing basics of DS/Algo and will be judging on it, imagine what it would have been working in company with such employees.