Advent of code 2023

See adventofcode.com/2023. The site uses some OAuth providers for authentication (to see the puzzle descriptions and submit solutions). Puzzle description page URLs look like adventofcode.com/2023/day/1.

Day 1

$ cd day/1
$ nix-shell -p cargo
$ cargo new solve # But this was renamed, see below.
$ cargo ./input.txt
...
Sum: 52834
$ rm -r .git

I could have used cargo new --vcs none solve to prevent the creation of the .git/ directory.

I've created a day/1/solve/ directory structure, but I should have used day/1/ instead (same for the following days). The puzzle input files are outside of solve/ (i.e. day/1/input.txt for instance).

When implementing the multicall binary (see below after Day 10), I've removed the solve/ subdirectory, and renamed the package name from "solve" to "day1" in the Cargo.toml file.

Each participant receive their own input, so it's ok to publish the results. (And keeping them here helps during refactoring.)

In addition of input.txt, there is also a shorter example.txt file.

Day 2

It seems I need rustc 1.61 (the above provided 1.60) to build nom 7.1.3. So I've updated my nixos-unstable channel. (It's possible my stable channel is quite old too.) This brings me to rustc 1.73.

$ cd day/2
$ nix-shell -I nixpkgs=channel:nixos-unstable -p cargo

$ cargo run ./input.txt
...
Sum: 2176
Sum of powers: 63700

Day 3

$ cargo run ./input.txt
...
Part one: 525181
Part two: 84289137

Day 4

$ cargo run ./input.txt
...
Part two: 14624680

Day 5

Use

$ time cargo run --release ./input.txt
...
Part one: Some(322500873)
Part two: 108956227
real    1m46.364s
user    1m46.349s
sys     0m0.012s

(Part one is available much earlier.)

I guess that instead of resolving individual numbers (seeds), I should resolve ranges. So that after each "stage", the output is one (best case) or multiple ranges. And before proceeding to next stage, ranges that are "compaptible" could be merged together.

Day 6

For part two, I simply changed the input.txt file manually.

$ cargo run ./input-part-1.txt
...
Part one: 24655068

$ cargo run ./input.txt
...
Part one: 24655068

Day 7

The code corresponds to part two. Part one is commented out/changed.

$ cargo run ./input.txt
...
Part one: 251824095

Day 8

$ cargo run ./input.txt
...
Part one: 16409
["QXA", "PDA", "TDA", "QQA", "PPA", "AAA"]
QXA: 12643
PDA: 14257
TDA: 15871
QQA: 18023
PPA: 19637
AAA: 16409
Part two: 11795205644011

Day 9

$ cargo run ./input.txt
...
Part two: 1112

Day 10

$ cargo run --release ./input.txt
...
Part one: 6599

I havn't made part 2.

Multi-calls

A binary to run all puzzles is given too.

$ cargo new --vcs none multicall
$ cargo run -- --day 1 ../day/1/input.txt
...
Sum: 52834

noteed/adventofcode-2023