AdventOfCode2021_Julia VS advent_of_code

This has been a very fun year of puzzles. Looking forward to not having my alarm set for 05:45 in the morning any more. This year I've done everything in Julia to be fast (usually placed around 1000 for both parts), then trying to make nicer solutions in Rust later in the day, and then trying to make solutions in C, which this year meant that I would be implementing a Priority queue. The C repo is not quite complete. Missing a working solution for day 3 part 2 so far (Tried to be really big brain there, did not work out, and I haven't bothered going back yet), and day 23-25 is not yet completed. The rust repo should have working solutions for all days.

My part2_memo() solution here in julia runs in under 1ms timed with @btime.

After a bit of cleanup, mine is taking 230µs: https://github.com/MarcusTL12/AdventOfCode2021_Julia/blob/main/src/day9.jl

Here's the relevant extract from my (recursive) solution. Full code on GitHub.

Like others, I used lcm. Here's an extract of the solution, omitting parsing and main(). Full solution on GitHub.

Solutions to parts 1 and 2 nearly identical and pretty much worked first time. Nothing clever here. This was far simpler than I thought it would be. I probably spent most time trying to think of a mathematical way of getting all points between p1 and p2. In the end, I just constructed two ranges. Full code here.

Full code on github.

The core of my solution below using numpy (because I'm learning it!). See github for full code.

Python 3 solution using numpy. I got held up because I assume (but know better) that numpy arrays are [x,y] instead of [row, col], which is [y,x].

Below is the new solution, which works for part 1 and 2. The full code is on GitHub.

These are the key functions. The whole code is on GitHub

Part 2 (extract shown below) was a matter of starting with the low points found in part 1 then recursively looking around for relevant points. Full code on GitHub

Code is on GitHub.