See me write these live on Twitch at UTC 05:00, just as the puzzle opens. The VODs are typically available for a week or so.
Links to years with some solution explanations:
Years are each a separate Gradle submodule. For fun I solve most of the puzzles three times:
- a functional solution, the code must be 100% pure and immutable, no
var, noMutableListetc. Some leeway here is helper functions in thelibsfolder, some of these may not be implemented completely functionally but in that case the API surface has to be functional and the data structures used must remain immutable. - an imperative solution, mutable state is allowed and I use for loops and the likes freely.
- a fast solution, where I try to write as fast Kotlin code as possible while giving zero consideration to code readability. Starting from 2022 I started using JMH to benchmark these solutions.
If a solution has multiple variants I use _func, _imp and _fast suffixes for these.
During 2021 I wrote a bunch of small utilities and data structures to help me solve the puzzles. A non-exhausting list:
- A generic base class for writing solutions - they take a
Parserand have two overridable methods calledpart1andpart2. Both of these are expected to return a subclass ofNumber. - A
Parserframework to massage the input data - Common data structures for representing input, a
Grid - (with a
MutableGridimperative variant) and aGraph - Vec2i and Vec4i to help solving 2D and 3D puzzles, respectively
- A small utils for common collection & string operations