aoc2021 VS advent_of_code

I've done something similar to this in Python before, but this time the completion aspect did throw a little wrinkle into it. That taught me some new stuff about slices, sorting, and idiomatic implementations of a stack in Go. Full source including tests available on Github.

In the spirit of "premature optimization is the root of all evil, I just brute forced it. The test suite ran in 70ms on my system so that was good enough for me not to worry about further optimization.

Yes! https://github.com/krmaxwell/aoc2021 organized by days.

Like most other folks, I did the naive approach for part 1 and then part 2 was untenable. Props to everyone who did the smart thing from the beginning. As always, my full code including tests is on Github.

This one kicked my ass for a while, which was confusing because the tests all passed fine with example data. Eventually I tracked down the problem to the way I was reading in the actual puzzle input... I should've known. Anyway, in addition to the [Github repo](https://github.com/krmaxwell/aoc2021/master/day4] with full tests and stuff, here's the core answer:

Same as yesterday, my answers using Go are on Github with a TDD-ish approach. I'm not being super strict with TDD here.

My solution for Day 1 is on GitHub. I think you may have made things significantly more complicated than needed.

I'm trying in Go this year, just because I'm working on learning it.

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.