CodeWars/6kyu/simple_substitution_cipher_helper/solution.rs

pub struct Cipher {
    decoded: Vec<u8>,
    encoded: Vec<u8>,
}

impl Cipher {
    pub fn new(map1: &str, map2: &str) -> Cipher {
        Cipher {
            decoded: map1.as_bytes().to_vec(),
            encoded: map2.as_bytes().to_vec(),
        }
    }

    pub fn encode(&self, string: &str) -> String {
        String::from_utf8(
            string
                .bytes()
                .map(|c| match self.decoded.iter().position(|x| x == &c) {
                    Some(i) => self.encoded[i],
                    None => c,
                })
                .collect::<Vec<u8>>(),
        )
        .unwrap()
    }

    pub fn decode(&self, string: &str) -> String {
        String::from_utf8(
            string
                .bytes()
                .map(|c| match self.encoded.iter().position(|x| x == &c) {
                    Some(i) => self.decoded[i],
                    None => c,
                })
                .collect::<Vec<u8>>(),
        )
        .unwrap()
    }
}