Method digit

src/helper.rs:17–23

(self, d: i32)

    impl Digit<i32> for i32 {
        fn digit(self, d: i32) -> String {
            let mut s = self.to_string();
            let space = " ".repeat((d as usize) - s.len());
            s.push_str(&space);

            s
        }
    }

    impl Digit<i32> for String {