Advent of Code 2023

Advent of Code 2023

Odd numbered days (1st December, 3rd December, etc) are in C++23, where as even numbered days are in Rust. This is because I wanted to practise both but did not want to commit to doing each challenge twice (and they are more fun the first time round).

Odd days: C++23

Compiled and run from repo root with g++ --std=c++23 -O3 -fopenmp -lpthread -Wall -Wextra -pedantic day1/a/main.cpp -o day1/build/1a, etc. Locally on Arch (btw) the --std flag is required to allow for std::views though this still flags as an error in vscode...

Even days: Rust 1.74.0

Compiled and run from cargo root with the good 'ol cargo run --release.

Run

Or you can build and run with:

# cpp or rust
./run 1         # build and run day 1 with time

# cpp
./run 1 1,2     # same as `./run 1`
./run 1 1       # build and run only day 1 part 1

Results

Day	Part One	Part Two	Execution Time
1	56049	54530	0.002s [1]
2	2679	77607	0.001s
3	522726	81721933	0.005s [2]
4	23941	5571760	0.002s
5	806029445	59370572	2m24.628s [3]
6	2756160	34788142	0.001s
7	254024898	254115617	0.002s [4]
8	20777	13289612809129	0.030s

[1] - Part one and part two were separate executables taking 0.001s and 0.002s respectively, combining would likely be less than the sum of execution times

[2] - Due to naive algorithm which iterated over all part and symbol lexemes in O(|N| * |S|), could be made faster by only checking the symbols in rows (n-1) to (n+1), not 0..N, for a part on row n. But this was deemed pointless given that it was a single run on once input of only 140x140 possible symbols (reality: 730) and 70x140 numbers (reality: 1192) the execution was basically instant.

[3] - Todo: fast version as described in notes.

[4] - Todo: make the card strength functions more generalised rather than many if-else statements, also generalise the simple/complex rules.