Advent of Code

This is repository holds my solutions to the Advent of Code puzzles.

Using

1. export AOC_SESSION=D34DBEEF before running to get input dynamically from AoC server. How to get session cookie.
2. cd YYYY; cargo run 4 runs just Day04.rs
3. cargo run all runs all days
4. cargo run --release all for fastest benchmark
5. cargo test --doc runs all tests
6. AOC_RENDER=1 cargo run all to render visualizations (if implemented)

Annual Thoughts

• 2025: Rust & more visualizations
• 2024: Rustaceans assemble! Focusing on faster solutions this year. Caching in rust feels quite clumsy compared to python's @lru_cache decorator.
• 2023: Going with rust again!
• 2022: Using this as an opportunity to learn rust. I did use python on some of the puzzles where I was racing against colleagues. :D

Visualizations

2025 Day04: Printing Department

2025 Day03: Lobby

2025 Day01: Secret Entrance

2024 Day18: RAM Run

2024 Day14: Restroom Redoubt

2022 Day15: Beacon Exclusion Zone

Most Useful Crates

Serde

use serde::{Deserialize,Serialize};#[derive(Serialize,Deserialize,Debug)]structPart{x:usize,m:usize,a:usize,s:usize,}// then laterlet json_line:&str = "{x=787,m=2655,a=1222,s=2876}";let some_part:Part = serde_json::from_str(&json_line).unwrap();// and it adds the debug print so you canprintln!("{:?}", some_part)

ProgressBar

let max = 777u64;use indicatif::{ProgressBar,ProgressStyle};let progress = ProgressBar::new(max);
progress.set_style(ProgressStyle::with_template("{bar:40.cyan/blue} {pos:>9}/{len:9} [{eta} left] {msg}",).unwrap(),);
progress.set_message("finding repeating sequence...");for idx in0..max {// do something
progress.set_position(idx asu64);}
progress.finish_with_message("Done");

Rayon

use rayon::prelude::*;use std::sync::atomic::{AtomicUsize,Ordering};
acc = AtomicUsize::new(0);
lines.par_iter().for_each(|line| {// do something
acc.fetch_add(1,Ordering::Relaxed);})let final_acc = acc.load(Ordering::Relaxed);

Requirements

• libssl needed for aoc input fetch
• ffmpeg needed for animated GIFs (2024 day14)

apt install libssl-dev ffmpeg