const INPUT: &str = "iwrupvqb";

fn solve(input: &str, desired_start: &str) -> u64 {
    let mut postfix = 1;
    loop {
        let digest = md5::compute(format!("{input}{postfix}"));
        let digest = format!("{:x?}", digest);

        if digest.starts_with(desired_start) {
            return postfix;
        }

        postfix += 1;
    }
}

fn main() {
    println!("Hello, this is Patrick!");

    let first_result = solve(INPUT, "00000");

    println!(
        "Santa needs to use a safer hashing, but his result is: {}",
        first_result
    );

    let second_result = solve(INPUT, "000000");

    println!(
        "The extra zero costs a lot and has the answer: {}",
        second_result
    );
}

#[test]
fn test_first1() {
    let s = solve("abcdef", "00000");

    assert_eq!(s, 609043);
}

#[test]
fn test_first2() {
    let s = solve("pqrstuv", "00000");

    assert_eq!(s, 1048970);
}