fn main() {
    // 入力
    let n = input::<usize>();
    let a = input::<usize>();

    // 何らかの処理

    // 出力
    println!("{}", max_ave);
    println!("{}", cnt);
}

#[cfg(test)]
mod tests {
    #[test]
    fn tester() {
        // テストケースをここに書く
        // (入力, 期待する出力) 
        let inputs = [
("
5 2 2
1 2 3 4 5
", "
4.500000
1
"),

("
4 2 3
10 20 10 10
", "
15.000000
3
"),
       ];

        for (input, expected) in inputs.iter() {
            call(input, expected.to_string());
        }
    }

    fn call<T: AsRef<str>>(input: T, expected: String) {
        use std::process::{Command, Stdio};
        use std::io::{Read, Write};

        let mut cmd_echo = Command::new("echo")
            .arg(input.as_ref())
            .stdout(Stdio::piped())
            .spawn()
            .unwrap();
        let mut cmd_run = Command::new("cargo")
            .arg("run")
            .stdin(Stdio::piped())
            .stdout(Stdio::piped())
            .spawn()
            .unwrap();

        // 実行と標準出力の受け取り
        if let Some(ref mut stdout) = cmd_echo.stdout {
            if let Some(ref mut stdin) = cmd_run.stdin {
                let mut buf: Vec<u8> = Vec::new();
                stdout.read_to_end(&mut buf).unwrap();
                stdin.write_all(&buf).unwrap();
            }
        }

        let res = cmd_run.wait_with_output().unwrap().stdout;
        let res_string = String::from_utf8(res.to_vec()).unwrap();

        // convert '\n' into space
        let actual = res_string
            .replace("\n", " ")
            .trim_end_matches(' ')
            .trim_start_matches(' ')
            .to_owned();
        let expected = expected
            .replace("\n", " ")
            .trim_end_matches(' ')
            .trim_start_matches(' ')
            .to_owned();

        // split into a vector
        let actual = actual
            .split(' ')
            .map(|s| s.parse::<f64>().unwrap())
            .collect::<Vec<_>>();
        let expected = expected
            .split(' ')
            .map(|s| s.parse::<f64>().unwrap())
            .collect::<Vec<_>>();

        assert_eq!(actual, expected);
    }
}

$ cargo test