mine.rs

gistfile1.txt

use sha2::{Digest, Sha256};
fn main() {
    println!("Answer is {:?}", rust_mine("hello"));
}
pub fn rust_mine(text: &str) -> String {
    let mut hasher = Sha256::new();
    (0..std::usize::MAX)
        .find_map(|nonce| {
            hasher.input(&format!("{}{}", text, nonce));
            let result = hasher.clone().result();
            // Ensure the first two hex digets match, then we only want to check the part of the
            // 3rd hex digit.
            //
            // 11 >> 4 # => 0
            // 12 >> 4 # => 0
            // 22 >> 4 # => 1
            if &result[0..2] == &[0, 0] && result[2] >> 4 == 0 {
                Some(format!("{:x}", result))
            } else {
                None
            }
        })
        .expect("unable to find answer")
}
#[cfg(test)]
mod tests {
    use super::*;
    #[test]
    fn it_works() {
        assert_eq!(
            rust_mine("hello"),
            "00000ae1e9539146cffff9f6e177926993877055191da80dba6171711f33b363".to_string()
        );
    }
}

Yeah wow that hex matching is way faster then the string and splice