AoC 2023 day 1

fn main() {
    let input = std::fs::read_to_string("../inputs/input.txt").unwrap();
    println!("{}", input);
    part_1(&input);
    part_2(&input);
}

fn part_1(input: &str) {
    let sum: u64 = input
        .lines()
        .map(|line| {
            let numbers: Vec<char> = line.chars().filter(|c| c.is_ascii_digit()).collect();
            let number_string = format!("{}{}", numbers.first().unwrap(), numbers.last().unwrap());
            number_string.parse::<u64>().unwrap()
        })
        .sum();
    println!("part 1: {}", sum);
}

fn part_2(input: &str) {
    let number_words = [
        "one", "two", "three", "four", "five", "six", "seven", "eight", "nine",
    ];

    let sum: u64 = input
        .lines()
        .map(|line| {
            let chars: Vec<char> = line.chars().collect();
            let mut numbers = Vec::new();

            for (i, c) in line.chars().enumerate() {
                if c.is_ascii_digit() {
                    numbers.push(chars[i].to_string());
                } else {
                    let remaining: String = chars[i..].iter().collect();
                    let pos = number_words
                        .iter()
                        .position(|word| remaining.starts_with(word));

                    if let Some(pos) = pos {
                        numbers.push((pos + 1).to_string());
                    }
                }
            }

            format!("{}{}", numbers.first().unwrap(), numbers.last().unwrap())
                .parse::<u64>()
                .unwrap()
        })
        .sum();

    println!("part 2: {}", sum);
}