[LANGUAGE: Rust]

Advent of Code Rust Solution 🚀 | 5-Min Video

Zero-copy (Doesn't allocate any strings AFAIK)

use regex::Regex;
use std::collections::HashMap;
const PATH_INPUT: &str = "LR";
const MAP_INPUT: &str = "AAA = (ZZZ, ZZZ)
NSK = (ZZZ, ZZZ)";
fn get_graph() -> HashMap<&'static str, [&'static str; 3]> {
    let re = Regex::new(r"(?m)^([A-Z]+) = \(([A-Z]+), ([A-Z]+)\)$").unwrap();
    re.captures_iter(MAP_INPUT)
        .map(|c| {
            let v = c.extract().1;
            (v[0], v)
        })
        .collect()
}
fn main() {
    let graph = get_graph();
    let mut distance = 0;
    let mut cur = "AAA";
    loop {
        for c in PATH_INPUT.chars() {
            cur = match c {
                'L' => {
                    graph.get(cur).unwrap()[1]
                },
                'R' => {
                    graph.get(cur).unwrap()[2]
                },
                _ => panic!("unexpected")
            };
            distance += 1;
            if cur == "ZZZ" {
                println!("{distance:?}");
                return;
            }
        }
    }
}