I'd really rather not tell you our database schema.

Instead of expecting businesses to tell you domain specific things and then answer questions about them, please just understand some basic principles behind a large class of algorithms.

Almost all algorithm questions boil down to a simple principle, can you take a problem and break it down into its simplest form; the simplest linked list to reverse is the empty linked list or a linked list with 1 node.

Can you then build upon the simplest case to solve the next simplest case; reverse a multi-node linked list by reversing the tail and then appending the head to the result.

It really is unfortunate how many people, instead of trying to understand concepts, want to just memorize a bunch of hardcoded facts or trivia about programming languages or libraries. If you understand the basic principles, you can easily pick up minutia about C++ copy constructors or move constructors... but someone who has memorized a great deal of minutiae about C++ may never be able to understand some of the basic principles that broadly cover a multitude of data structures and algorithms.