How to Work at Google: Example Coding/Engineering Interview

Am I understanding that these are the kind of questions that people often memorise?

Quite a lot of this video, was the interviewee following logic, and solving a very solvable problem. It doesn't look like a memorisation exercise to me. It would be so obvious if he already knew the answer.

Although asking for the code seemed a bit redundant, when his solutions could be coded up by anyone following along.