We can use FIleMaker files to work out the problem. The file can be simple or complex.
You could also create your own.
Here's a pic of mine from last year.
It's a pretty simple file containing a few fields:
1. Puzzle 1 text
2 Puzzle 2 text
3. Puzzle Day
4. Puzzle data
5. Answer field
In this file, you'd write a script or calcs or whatever to solve the puzzle and then post to the Advent of Code site.