aoc-2021

Advent of code 2021 solutions in Rust.

Running solutions

A nightly version of rust is required. Solutions can be run with:

cargo run --release --bin day<X>

where X is the day number.

• If you want to download inputs automatically you have to put your session cookie of AoC in a file named session. It should be in the format session=<hex>.
• Alternatively, you can create the files manually in the inputs folder, inputs for day x are read from x.txt.

To benchmark a solution, pass the --bench flag and optimize the binary for your specific CPU like this:

RUSTFLAGS="-C target-cpu=native" cargo run --release --bin day<X> -- --bench

Benchmark results

These are the benchmark results on my PC. Keep in mind the time is measured from the moment the input text is in memory until the final answer is calculated.

Day	Part 1	Part 2
1	22.393 µs	22.394 µs
2	24.492 µs	24.672 µs
3	479 ns	5.42 µs
4	37.051 µs	73.21 µs
5	332.156 µs	471.851 µs
6	226 ns	374 ns
7	21.255 µs	32.354 µs
8	11.348 µs	51.588 µs
9	4.993 µs	15.525 µs
10	8.297 µs	8.665 µs
11	5.941 µs	26.288 µs