Apex SystemsHardCoding00:00

Welcome to your interview for the Machine Learning Engineer role at Apex Systems.
The question is on your right: Optimize to O(n log n). 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. You have three graded attempts to score 7/10 or better.
How would you optimize a function to run in O(n log n) time complexity?