Welcome to your interview.
The question is on your right: Optimizing Array/String Algorithms. Take a moment with it first.
Talk your thinking through with me if you like - when you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes). Discussion and graded submissions share your five interviewer interactions, so spend them well.
Given an array or string manipulation problem, how would you optimize for time and space complexity?