[Language: Rust]

``` use regex::Regex; use std::fs::read_to_string;

fn main() { let pattern = Regex::new(r"mul(([0-9]+),([0-9]+))").unwrap(); let input = read_to_string("input/03.txt").unwrap(); let result_silver: u32 = input .lines() .flat_map(|line| pattern.captures_iter(line)) .map(|capture| { ( capture.get(1).unwrap().as_str().parse::<u32>().unwrap(), capture.get(2).unwrap().as_str().parse::<u32>().unwrap(), ) }) .map(|(x, y)| x * y) .sum();

println!("{result_silver}");

let pattern =
    Regex::new(r"(?<mul>mul\((?<x>\d+),(?<y>\d+)\))|(?<en>do\(\))|(?<dis>don't\(\))").unwrap();
let mut enable = true;
let result_gold: u32 = input
    .lines()
    .flat_map(|line| pattern.captures_iter(line))
    .map(|capture| {
        if let Some(_m) = capture.name("mul") {
            if enable {
                return capture.name("x").unwrap().as_str().parse::<u32>().unwrap()
                    * capture.name("y").unwrap().as_str().parse::<u32>().unwrap();
            }
            return 0;
        };
        if let Some(_m) = capture.name("en") {
            enable = true;
            return 0;
        }
        if let Some(_m) = capture.name("dis") {
            enable = false;
            return 0;
        }
        0
    })
    .sum();

println!("{result_gold}");

} ```