Your question is Explain Two Sum Complexity. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
Explain the time complexity of solving Two Sum on an unsorted array using both a brute-force nested-loop approach and a hash-table approach. Justify why the optimized solution is linear on average.