Simple Codeforces Rust template

main.rs

use std::io::Write;

#[rustfmt::skip]
macro_rules! define_read {
    ($words:ident) => {
        macro_rules! read {
            () => {
                $words.next().unwrap().parse().unwrap()
            };
            ($t:ty) => {
                $words.next().unwrap().parse::<$t>().unwrap()
            };
            ($t:ty; $n:expr) => {
                read!($t, |a| a; $n)
            };
            ($t:ty, decr; $n: expr) => {
                read!($t, |a| a - 1; $n)
            };
            ($t:ty, $f:expr; $n: expr) => {
                $words
                    .by_ref()
                    .take($n)
                    .map(|s| s.parse::<$t>().unwrap())
                    .map($f)
                    .collect::<Vec<_>>()
            };
        }
    };
}

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let mut input = String::new();
    std::io::Read::read_to_string(&mut std::io::stdin(), &mut input).unwrap();
    let mut words = input.split_whitespace();

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

    define_read!(words);

    // BEGIN SOLUTION

    for _ in 0..read!(i64) {}

    Ok(())
}