From last year: hot springs, the pipes problem, gears, pulses, range math.. half the problem is turning the text input into the correct data structures to solve it.
yes, that kinda is what the reality of programming is. Correctly representing the problem so that the solution easily follows. Various famous people have various quotes about this, for example Rob Pike: "if you've chosen the right data structures and organized things well, the algorithms will almost always be self-evident".
