use std::fs;

fn extract_number(line: &str) -> u32 {
    let mut has_digit: bool = false;
    let mut first: u32 = 0;
    let mut last: u32 = 0;
    for character in line.chars() {
        if character.is_digit(10) {
            if !has_digit {
                has_digit = true;
                first = character.to_digit(10).unwrap();
            }
            last = character.to_digit(10).unwrap();
        }
    }
    let number: u32 = first * 10 + last;
    number
}

fn main() {
    let input_filename: &str = "../data/input.txt";

    let contents =
        fs::read_to_string(input_filename).expect("Should have been able to read the file");

    let mut sum: u32 = 0;
    for line in contents.lines() {
        let number = extract_number(line);
        // println!("{:?}", number);
        sum += number;
    }
    println!("{:?}", sum);
}