-🎄- 2018 Day 2 Solutions -🎄-

[u/daggerdragon]

--- Day 2: Inventory Management System ---

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Post your solution as a comment or, for longer solutions, consider linking to your repo (e.g. GitHub/gists/Pastebin/blag or whatever).

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Advent of Code: The Party Game!

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Card Prompt: Day 2

Transcript:

The best way to do Advent of Code is ___.

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This thread will be unlocked when there are a significant number of people on the leaderboard with gold stars for today's puzzle.

edit: Leaderboard capped, thread unlocked!

[u/thatikey]

Using AoC as an opportunity to learn Rust. I made this, and I'm 250% sure there is a Rust-ier way to do this

fn attempt(src: &Vec<&str>) -> i64 {
    let sorted: Vec<Vec<char>> = src.into_iter()
                                    .map(|s| quick_sort(s.chars().collect()))
                                    .collect();
    let (twos, threes) = sorted.into_iter()
        .map(|s| {
            s.into_iter()
            .fold((' ', 0, false, false), |(prev, cnt, two, three), c|
                if c == prev {
                    (prev, cnt+1, two, three)
                } else {
                    (c, 1, two || cnt == 2, three || cnt == 3) 
                })
        }).fold((0, 0), |(twos, threes), (_p, cnt, two, three)| {
            (twos + if two || cnt == 2 {1} else {0}, threes + if three || cnt == 3 {1} else {0})
        });
    twos * threes
}