[tobiasSoftware]

I agree that "throw everything in a hashmap" should be straightforward and is a good interview test. However, his further steps to "optimize" it by saying "Poor candidates load the contents of both files into memory." are terrible. Yes, that might optimize resources, but first it hardcodes the requirement that there are exactly two days breaking the solution if the requirement changes, and second it adds a bunch of finicky fragile code about "if there are two pages or more from day one or if the first page from day one is different from the page from day two".

Great candidates treat software like a business with changing requirements and code that is read by multiple people, poor candidates treat software like a math challenge where the only goal is to use as few resources as possible.