Advent of Code Day 5

extern crate crypto;

use crypto::md5::Md5;
use crypto::digest::Digest;

fn main() {
    let mut sh = Md5::new();

    sh.input_str("ojvtpuvg");

    let mut idx = 0;
    let mut s = vec!['_','_','_','_','_','_','_','_',];
    loop {
        let mut sh1 = sh.clone();
        sh1.input_str(&idx.to_string());
        idx += 1;
        let res = sh1.result_str();
        if res.starts_with("00000") {
            println!("{}", res.as_bytes()[5] as char);
            let i = res.as_bytes()[5] as usize - ('0' as usize);
            if i < 8 && s[i] == '_' {
                s[i] = res.as_bytes()[6] as char;
                println!("{:?}", s);
            }
        }
    }
}