fizzbuzz.rs

extern crate numtoa;

/*
real    0m1.080s
user    0m0.684s
sys     0m0.392s
*/
fn one() {
    let mut i: i32 = 0;
    while i < 10000000 {
        println!(
            "{}\n{}\nFizz\n{}\nBuzz\nFizz\n{}\n{}\nFizz\nBuzz\n{}\nFizz\n{}\n{}\nFizzBuzz\n",
            i+1, i+2, /*Fizz*/ i+4, /*Buzz*/
            /*Fizz*/ i+7, i+8, /*Fizz Buzz*/
            i+11, /*Fizz*/ i+13, i+14 /*FizzBuzz*/
        );
        i += 15;
    }
}

/*
real    0m0.205s
user    0m0.196s
sys     0m0.008s
*/
fn two() {
    use std::io::{BufWriter,Write};
    let stdout = std::io::stdout();
    let out = stdout.lock();
    let mut out = BufWriter::new(out); //< Biggest gain

    let mut i: i32 = 0;
    while i < 10000000 {
        let _ = write!(
            &mut out,
            "{}\n{}\nFizz\n{}\nBuzz\nFizz\n{}\n{}\nFizz\nBuzz\n{}\nFizz\n{}\n{}\nFizzBuzz\n",
            i+1, i+2, /*Fizz*/ i+4, /*Buzz*/
            /*Fizz*/ i+7, i+8, /*Fizz Buzz*/
            i+11, /*Fizz*/ i+13, i+14 /*FizzBuzz*/
        );
        i += 15;
    }
}

macro_rules! num {
    ($out:ident, $buf:ident, $num:expr) => {
        let start = $num.numtoa(10, &mut $buf);
        let _ = $out.write(&$buf[start..]);
        let _ = $out.write(b"\n");
    }
}

/*
real    0m0.190s
user    0m0.188s
sys     0m0.000s
*/
fn three() {
    use std::io::{BufWriter, Write};
    use numtoa::NumToA;

    let stdout = std::io::stdout();
    let out = stdout.lock();
    let mut out = BufWriter::new(out);

    let mut buffer = [0u8; 20];

    let mut i: i32 = 0;
    while i < 10000000 {
        num!(out, buffer, i+1);
        num!(out, buffer, i+2);
        let _ = out.write(b"fizz\n");
        num!(out, buffer, i+4);
        let _ = out.write(b"buzz\n");
        let _ = out.write(b"fizz\n");
        num!(out, buffer, i+7);
        num!(out, buffer, i+8);
        let _ = out.write(b"fizz\n");
        let _ = out.write(b"buzz\n");
        num!(out, buffer, i+11);
        let _ = out.write(b"fizz\n");
        num!(out, buffer, i+13);
        num!(out, buffer, i+14);
        let _ = out.write(b"fizzbuzz\n");
        i += 15;
    }
}

fn main() {
    three()
}