FastBuzz

fast_buzz.rs

extern crate itoa;

use std::io::Write;
use std::io::BufWriter;

pub fn main() {
    let stdout = std::io::stdout();
    let mut stdout = BufWriter::new(stdout);

    let mut acc = 810092048;
    for i in 1..100_000_000_u32 {
        let c = acc & 3;
        match c {
            0 => {
                itoa::write(&mut stdout, i).unwrap();
                stdout.write(b"\n").unwrap();
            },
            1 => {
                stdout.write(b"Fizz\n").unwrap();
            },
            2 => {
                stdout.write(b"Buzz\n").unwrap();
            },
            3 => {
                stdout.write(b"FizzBuzz\n").unwrap();
            },
            _ => { unimplemented!() }
        }

        acc = acc >> 2 | c << 28
    }
}