adventofcode VS aoc-2020

Hmm, interesting! I'm definitely not getting the input on compile time either. I'm using a function in my util mod to either get it from the web (for the first time and store it) or read from a file (I did the flamegraph not on the first run). I see you are using std::fs::read_to_string to read your file. I'm using another method to read the files in a similar way but also use a BufReader in the middle of it. I'm not sure if it can make that of a difference but that seems like the only difference considering the rest of the parsing looks similar with iter/map stuff.

RUST

Figured I'd post my benches as well, see below. Everything done in Rust (link to source).

Here's my day 24 in Rust, using SIMD as usual :) (and offset coordinate encoding to make a SIMD-friendly 2-D cell grid)

Borrowed both ideas in my version :) On my input your version runs at 3ms, mine in 1.5ms, so it might be faster on some inputs (link). I initially started with something similar to yours but then figured why not use 512-bit ints, so that the notion of 'head' and 'tail' disappears as your head then stays at position 0 (so, e.g., to remove a card, you just right-shift the whole bigint). Also used a tiny bit of simd along the way.

Part 1 + Part 2