Your question is Hardest Part of a Coding Session. 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).
Coding the solution to 3 questions in 45 mins was definitely the hardest part. But the interviewer helps and makes sure you dont get too tensed by talking to you through out the process.