This time around, we're porting a solution from C++ to Rust and seeing how it feels, how it performs, and what we can learn about both languages by doing that.

See Day 17 for the rationale re: porting solutions rather than writing my own from scratch. TL;DR is: it's better than nothing, and we can still focus about learning Rust rather than spending entire days fighting off-by-one errors.

Advent of Code gets harder and harder, and I'm not getting any smarter. Or any more free time. So, in order to close out this series anyway, I'm going to try and port other people's solutions from "language X" to Rust. That way, they already figured out the hard stuff, and we can just focus on the Rust bits!

Sounds good? Good. Let's proceed.

Let's tackle the day 16 puzzle!

The input looks like this:

Valve AA has flow rate=0; tunnels lead to valves DD, II, BB
Valve BB has flow rate=13; tunnels lead to valves CC, AA
Valve CC has flow rate=2; tunnels lead to valves DD, BB
Valve DD has flow rate=20; tunnels lead to valves CC, AA, EE
Valve EE has flow rate=3; tunnels lead to valves FF, DD
Valve FF has flow rate=0; tunnels lead to valves EE, GG
Valve GG has flow rate=0; tunnels lead to valves FF, HH
Valve HH has flow rate=22; tunnel leads to valve GG
Valve II has flow rate=0; tunnels lead to valves AA, JJ
Valve JJ has flow rate=21; tunnel leads to valve II

The day 15 puzzle falls into the "math puzzle" territory more than "let's learn something new about Rust", but since several folks asked if I was going to continue... let's continue.

The sample input is as follows:

Sensor at x=2, y=18: closest beacon is at x=-2, y=15
Sensor at x=9, y=16: closest beacon is at x=10, y=16
Sensor at x=13, y=2: closest beacon is at x=15, y=3
Sensor at x=12, y=14: closest beacon is at x=10, y=16
Sensor at x=10, y=20: closest beacon is at x=10, y=16
Sensor at x=14, y=17: closest beacon is at x=10, y=16
Sensor at x=8, y=7: closest beacon is at x=2, y=10
Sensor at x=2, y=0: closest beacon is at x=2, y=10
Sensor at x=0, y=11: closest beacon is at x=2, y=10
Sensor at x=20, y=14: closest beacon is at x=25, y=17
Sensor at x=17, y=20: closest beacon is at x=21, y=22
Sensor at x=16, y=7: closest beacon is at x=15, y=3
Sensor at x=14, y=3: closest beacon is at x=15, y=3
Sensor at x=20, y=1: closest beacon is at x=15, y=3

I like how the day 14 puzzle sounds, because I think it'll give me an opportunity to show off yet another way to have Rust embedded in a web page.

But first...

Let me guess: parsing?

You bet your furry ass, parsing.

The input looks something like this:

498,4 -> 498,6 -> 496,6
503,4 -> 502,4 -> 502,9 -> 494,9

And each line is essentially... a polyline: we're supposed to draw lines between every point on the path, and that determines rocks on the map.

The day 13 puzzle needs a speech therapist.

???

...because it has an awful lisp!! Ahhhahahahhhh

Are you ok? What is.. what is going on with you?

No but seriously we have what are ostensibly S-expressions, except they use JSON-adjacent notation:

[1,1,3,1,1]
[1,1,5,1,1]

[[1],[2,3,4]]
[[1],4]

[9]
[[8,7,6]]

[[4,4],4,4]
[[4,4],4,4,4]

[7,7,7,7]
[7,7,7]

[]
[3]

[[[]]]
[[]]

[1,[2,[3,[4,[5,6,7]]]],8,9]
[1,[2,[3,[4,[5,6,0]]]],8,9]

Alright! The day 12 puzzle involves path finding, and it seems like a good time to lean more heavily on the WASM embeds I've set up for the previous parts.

Let's start by setting up the types we'll want!

Our input is a heightmap, like so:

Sabqponm
abcryxxl
accszExk
acctuvwj
abdefghi

Where 'a'..='z' is a square with a given elevation (from lowest to highest), is the start, and is the end.

It's a new day, it's a new advent of code puzzle.

In that one, we have to apparently cosplay as an IBM mainframe and just.. crunch them numbers. This doesn't look fun, and I can't think of a clever twist to make it fun, so let's try to make it short and sweet.

Our input looks like this:

Monkey 0:
  Starting items  
  Operation new = old  
  Test divisible by 
    If true throw to monkey 
    If false throw to monkey 

Monkey 
  Starting items    
  Operation new = old + 
  Test divisible by 
    If true throw to monkey 
    If false throw to monkey 

etc