Advent of Code 2025

Practising my acquired knowledge of rust.

⚠️ NOTE ⚠️ Most of these solutions are uploaded without any sort of cleanup, so lower expectations on code readibility and abstraction.

Using the advent-of-code-rust template.

Running

# Simplest way to scaffold a day.
cargo today

# Scaffold a day and download its input.
cargo scaffold <day> --download

# Solve / submit.
cargo solve <day> [--release] [--submit]

# Time.
cargo time <day> [--all] [--store]

Testing

cargo test

When will I get bored?

• Day1
  • Part 1: 25.6µs @ 10000 samples
  • Part 2: 23.1µs @ 10000 samples
• Day2
  • Part 1: 4.9µs @ 10000 samples
  • Part 2: 17.1µs @ 10000 samples
• Day3
  • Part 1: 79.5µs @ 5043 samples
  • Part 2: 129.5µs @ 5177 samples
• Day4
  • Part 1: 572.1µs @ 879 samples
  • Part 2: 1.4ms @ 669 samples
• Day5
  • Part 1: 44.4µs @ 5347 samples
  • Part 2: 10.4µs @ 10000 samples
• Day6
  • Part 1: 32.3µs @ 7305 samples
  • Part 2: 43.9µs @ 9732 samples
• Day7
  • Part 1: 14.3µs @ 10000 samples
  • Part 2: 11.3µs @ 10000 samples
  • Removing the parsing step made it 4x faster, huh.
• Day8
  • Part 1: 619.1µs @ 519 samples
  • Part 2: 38.8ms @ 24 samples
  • Union-find & Kruskal ftw! Needs cleanup.
• Day9
  • Part 1: 77.5µs @ 10000 samples
  • Huuh, tried some convex hull stuff, but that does not make sense.
  • What this needs is the contour, I think, so Moore Neighbor tracing and check if every corner is inside?
• Day10
  • Part 1: 9.3ms @ 47 samples
  • Did not read properly.
  • Replaced my vecs with bitsets and now I need vecs for part 2...
• Day11
  • Part 1: 120.9µs @ 3290 samples
• Day12