The most difficult part is figuring out what they are measuring, and how they want you to solve the problem, there are hundreds of ways to solve a problem. And

The most difficult part is figuring out what they are measuring, and how they want you to solve the problem, there are hundreds of ways to solve a problem. And once you have a solution, there is no time to make it o(n) effective, or do micro optimizations. That's why I hate automated coding tests. If there is an actual person with you - talk to that person! Ask how they will measure your performace, and ask how they want the problem to be solved! Then explain how you are thinking - can't do that to an automated code test.