Focus was on solving the problem using hackerrank's whiteboard (live coding). I wasn't sure if they expected someone to actually come up with the solutions or just to see how you do under pressure.
Sigiloso
Was not able to provide working implementations for all edge cases on any problem. I don't want to spoil which problems. I found them later on leetcode and they are not in the top 150 interview questions. They were both rated Hard.