I was good at the algorithms and data structures part of my university course, but as a developer with ten years experience, I find it is very rare to actually use these now.
Far more important is how / when to index an database table, how to design the tables in the first place.
If I need an efficient algorithm, in most cases someone has written (and tested) it and put it in a library.
Bringing it full circle, a puzzle is just a peculiar form of algorithm, most of the time. You don't want to hire someone who will sit around thinking about graph puzzles and how to measure 4 liters when you only have a 5L and 3L beaker. Google it and get on with the job.
Far more important is how / when to index an database table, how to design the tables in the first place.
If I need an efficient algorithm, in most cases someone has written (and tested) it and put it in a library.