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use std::convert::From;
use std::iter::Step;
use std::ops::{Add, Div, Mul, Rem};

pub fn pow<T: Clone + Mul<Output = T> + From<bool>, F: Step + From<bool>>(x: T, y: F) -> T {
    (false.into()..y).fold(true.into(), |acc, _| x.clone() * acc)
}

pub fn pow_mod(x: u32, mut y: u32, z: u32) -> u32 {
    let mut t = 1;
    let mut tmp = x % z;
    while y > 0 {
        if y & 1 > 0 {
            t = t * tmp % z;
        }

        tmp = tmp * tmp % z;
        y = y >> 1;
    }
    return t;
}

pub fn div_rem<T: Clone + Div + Rem>(x: T, y: T) -> (<T as Div>::Output, <T as Rem>::Output) {
    (x.clone() / y.clone(), x % y)
}

pub fn div<T: Clone + Div>(x: T, y: T) -> <T as Div>::Output {
    x / y
}

pub fn rem<T: Clone + Rem>(x: T, y: T) -> <T as Rem>::Output {
    x % y
}

pub fn lcm(_x: u32, _y: u32) {}

/// greatest common divisor
pub fn gcd(_x: u32, _y: u32) {}

pub fn big_num_prime() {}

pub fn is_prime(_x: u32) {}

pub fn is_odd(_x: u32) {}

pub fn is_even(_x: u32) {}