the input parsers don't get increasingly complex over the days. The problems themselves do. Even on the most difficult days around 22 or 23, the inputs are all just lines of space separate ints or some grid of points or something, just like the trivial problems on days 1-3
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".
