aoc VS aoc-2020

1076/1738 — Raw solution (to refactor/possibly rewrite)

Solution

Busy day today, going back to sleep zzZZZ. Clean solution and walkthrough here later today (hopefully).

If you're using Python, you can check this guy walkthroughs, he's good at explaining things and uses many Python's features to write clean code. I'd suggest to try tackle a problem on your own, and whether you manage to get a solution or not, read his walkthrough, and re-implement a solution using his ideas. This is what I did two years ago and it was a big help for me, I was more and more able to come up with solutions without looking at what he did. I still check what he does today, but I always solve the problem on my own first now.

758/2614 — Soluzione Python 3 — Walkthrough (inglese)

Solutions and walkthroughs for most of the years.

Congrats /u/skifire13 per il rank #233 globale, nice!

I've tried it a few times and solutions were surprisingly elegant! E.g., 2020-01-p2.

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.