aoc2022 VS adventofcode

It may be a nifty hash table (no, it is!:)) but the whole program runs about 12x slower on an M1 than my version where I first determine the max dimensions and simply allocate a grid of booleans... So I wonder how much the 8x8 bitset breakup could improve. But bitsets are a C++ feature. In C, like NRK: https://github.com/ednl/aoc2022/blob/main/09.c (my "startstoptimer.c" and .h are in the same repo)

I also checked lines but only after doing a rotation by 45 degrees, so the lines are straight. Compiled in C, fastest run time on M1 was 26 µs: https://github.com/ednl/aoc2022/blob/main/15.c

Same code but with preprocessed input to make it all fit into memory, runs in 7 ms on an Arduino Uno! https://github.com/ednl/aoc2022/blob/main/aoc22-15/aoc22-15.ino

Complete program runs in 463 µs on Apple M1, 2.61 ms on Pi 4. See comments at the top of the source file for how I measured. My comparison function:

Not 100% sure this is Upping-The-Ante, maybe just Other. I wanted to share some benchmark results of my solution for today, day 11 with the 10,000 monkeys, and how I got there. I think the easiest way to compare performance is to use the same hardware, and nowadays fairly common & standardised hardware might be the Raspberry Pi 4. Although, you can't buy any for years now... Best score I got when running my solution on my Pi 4 home server is 15.6 ms.

I quickly saw that I could do "item = item modulo (product of all div-test numbers)" but the implementation took me a while in C without queues or circular buffers. But that's all part of the fun for me! I didn't look for further clever optimisations because the compiled program runs in 20 ms on a Raspberry Pi 4. That was fast enough for today, I thought. Source code: https://github.com/ednl/aoc2022/blob/main/11.c

Yay, embedded software engineering!! :) Short, fast & almost no memory needed in C: https://github.com/ednl/aoc2022/blob/main/10.c or the relevant bits:

That's great, but on what hardware? My solution in C runs in 0.8 ms average (0.6 ms minimum) using hyperfine to measure 1000 runs in a Mac Mini M1. Same on a Pi 4 in performance mode: 3.6 - 3.8 ms.

Well, it took me a while to realise that in part 1 you always have to check the whole row or column because a higher tree can come at any point ... And except for skipping the borders, I couldn't come up with any sort of clever optimisation that would help reduce the O(N^2) complexity. It still runs in under 1 ms on a Mac Mini M1 according to hyperfine. Full code 52 lines without space/comments: https://github.com/ednl/aoc2022/blob/main/08.c

Code on GitHub is currently a mess.

In the spirit of the Day 5 ALLEZ CUISINE! challenge to ELI5 (Explain Like I'm Five), here's a tasty explanation of how my algorithm works using only a large bucket of Red Vines and a knife. It says to use lined paper, but if you try this at home consider aligning things on a cutting board.

[Language: Jsonnet] (on GitHub)

Elixir code, thoughts

Elixir 1554/1502 code, reflections

Elixir 2506/3402 (24 minutes, 2 hours), code, thoughts

Bonus solution in Go (golang) because I was confused about why my Elixir solution didn't work and decided to implement from scratch in case I'd done something dumb. The Go one also got the wrong answer, but took less than 100ms instead of a minute, so I could try out lots of tweaks that didn't change the answer.

Elixir 2031/2641 after 3.25/6.5 hours! Code on GitHub

I spent time this afternoon sprucing up my helpers for the iex REPL. I spent a bunch of time poking at things in IEx the last couple days and wanted to make sure I would minimize keystrokes if I needed to debug things on my phone while drunk. Turns out Thursday night > Friday night > Saturday night in terms of difficulty, so all those macros have so far saved me zero seconds :-)