Advent Of Code 2022

https://adventofcode.com/2022 solutions in Rust.

Retrieve your daily input using your session cookie via:

cargo run --release -- --day <day> download --session <session>

The data is put in data/ and used directly at compile time.

To compute the execution time, use:

cargo run --release -- --day <day> execute --part <part>

To measure execution time for a particular day, use:

cargo run --release -- --day <day> benchmark --number <number> --current

Day 01: Calorie Counting

double iterator::fold() can be used too, but… Code

Day 02: Rock Paper Scissors

basic logic computation.

Sadly inpt crate is slow (>500µs to parse 2500 inputs), so went back to "manual" parsing. Code

Day 03: Rucksack Reorganization

rust iterators playground… Code

Day 04: Camp Cleanup

range comparisons. Code

Day 05: Supply Stacks

parsing harder than task. task 2 is in quick and dirty coded task 1. Code

Day 06: Tuning Trouble

scanning with 'appropriate' memory. naive code would have been:

use itertools::Itertools;

Solution::U64(
    input
        .chars()
        .tuple_windows()
        .enumerate()
        .skip_while(|(idx, (a, b, c, d))| ![a, b, c, d].iter().all_unique())
        .map(|(idx, _)| (idx + 4) as u64)
        .next()
        .unwrap())

which is 145µs for simple 4 wide deep scan, but mine is 24µs. Difference with 14 deep would have been huge of course… Code

Day 07: No Space Left On Device

Trees in rust are quite annoying to manipulate, so here is a basic hashmap based solution. Sadly this leads to too many string manipulations, we need a way to avoid them. Each part uses 165µs.

update: new version using tree, and without any String, reduced to 46µs. Code

Day 08: Treetop Tree House

inplace bitmask in a grid, to save as space as possible.

Code

Day 09: Rope Bridge

basic movement computations.

Code

Day 10: Cathode-Ray Tube

CPU register simulation, nothing special.

Code

Day 11: Monkey in the Middle

Unkown game, plenty of subtle unsaid conditions, weird parsing for no reason, … I should have done the atcoder.jp game. Solution weren't prime factor decomposition as I first guessed, but simple lowering value by detecting invariant!

Code

Day 12: Hill Climbing Algorithm

path searching, basic Dijkstra

Code

Day 13: Distress Signal

parsing possible without recursion

Code

Day 14: Regolith Reservoir

sand going down memory align to falling sand. no optimization to fill next to our current position (so… 6ms for part2!).

Code

Day 15: Beacon Exclusion Zone

part 1: basic geometry, but text was vague about becons already on the line. part 2 optimization: only edges of covered zones, with big step when possible, 3.5ms.

Code

Day 16: Proboscidea Volcanium

part 1: astar is coming part 2:

Code