【数论】Rust使用Miller-Rabin primality test判别素数

use std::io::{self, BufRead, Write};

fn is_prime_trivial(n: i128) -> bool {
    if n  i128 {
    let mut result = 1;
    a %= m;
    while b > 0 {
        if b % 2 != 0 {
            result = (result * a) % m;
        }
        b >>= 1;
        a = (a * a) % m;
    }
    result
}

fn is_prime(n: i128) -> bool {
    if n  i128 {
    if _n == 1 {
        return 1;
    } else if _n == 4 {
        return 4;
    } else {
        let mut n = _n;
        while !is_prime(n) {
            n -= 1;
        }
        return n;
    }
}

fn main() {
    let stdin = io::stdin();
    let mut lines = stdin.lock().lines();
    let t: i32 = lines.next().unwrap().unwrap().trim().parse().unwrap();

    let stdout = io::stdout();
    let mut writer = io::BufWriter::new(stdout.lock());
    for _ in 0..t {
        let n: i128 = lines.next().unwrap().unwrap().trim().parse().unwrap();
//         println!("n {}", is_prime(n));
        let result = solve(n);
        writeln!(&mut writer, "{}", result).unwrap();
    }
}