One note: Many of the books being listed are quite challenging to read cover to cover. For instance, "Introduction to Algorithms" (which is generally referred to as "CLRS" as an abbreviated form of the last names of the four authors) is the textbook for Georgia Tech's graduate introduction to algorithms course, and we probably only covered half of the material in it. Even just reading a quarter of that book (or of many of the others suggested here) would still be tremendously valuable.
Both book 1 and 2 are solid interview prep material. They were very helpful jumping into graph database development too. I was not expecting them to be that 'deep end of the pool' when someone recommended a set.
