aoc2021 VS advent_of_code

I've been doing similar (in three langs, though Ive fallen behind on go and rust over the past few days) -- https://github.com/A-UNDERSCORE-D/aoc2021/blob/main/aoc/go/util/slice.go is most of my generic go fun, lots of implementations of higher order functions and nice wrappers

Python source

As usual, first implementation. Actually started by doing sum(range(1, steps+1)), and after solving remembered that theres a math thing for that (sum(0..n) = n * (n + 1) / 2). Nothing super fancy other than that. Code Finally starting to see speedup from pypy. That JIT is amazing but has its costs.

https://github.com/A-UNDERSCORE-D/aoc2021/blob/main/aoc/go/six/06.go -- Nothing super fancy. Nice ability to pick arrays over slices here though. Probably contributes a bit of speedup.

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.