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// Copyright © 2026 Mikhail Hogrefe
//
// This file is part of Malachite.
//
// Malachite is free software: you can redistribute it and/or modify it under the terms of the GNU
// Lesser General Public License (LGPL) as published by the Free Software Foundation; either version
// 3 of the License, or (at your option) any later version. See <https://www.gnu.org/licenses/>.
use crate::num::arithmetic::traits::{Height, ModIsReduced};
use crate::num::basic::unsigneds::PrimitiveUnsigned;
use crate::unsigned_polynomial::UnsignedPolynomial;
impl<T: PrimitiveUnsigned> ModIsReduced<T> for UnsignedPolynomial<T> {
/// Returns whether a [`UnsignedPolynomial`] is reduced modulo a [`u64`] $m$; in other words,
/// whether every one of its coefficients is less than $m$.
///
/// Asking that of every coefficient is asking it of the largest, so this is a comparison
/// against the polynomial's [`Height`](Height::to_height). The zero polynomial has no
/// coefficients and is reduced modulo every $m$.
///
/// $m$ cannot be zero.
///
/// $f(p, m) = (\max_i p_i < m)$.
///
/// # Worst-case complexity
/// $T(n) = O(n)$
///
/// $M(n) = O(1)$
///
/// where $T$ is time, $M$ is additional memory, and $n$ is the number of coefficients.
///
/// # Panics
/// Panics if `m` is 0.
///
/// # Examples
/// ```
/// use core::str::FromStr;
/// use malachite_base::num::arithmetic::traits::ModIsReduced;
/// use malachite_base::unsigned_polynomial::UnsignedPolynomial;
///
/// // The coefficients are 2, 3, and 1, so 4 is large enough and 3 is not.
/// let p = UnsignedPolynomial::<u64>::from_str("x^2+3*x+2").unwrap();
/// assert_eq!(p.mod_is_reduced(&4), true);
/// assert_eq!(p.mod_is_reduced(&3), false);
///
/// // The zero polynomial is reduced modulo everything.
/// assert_eq!(
/// UnsignedPolynomial::<u64>::from_str("0")
/// .unwrap()
/// .mod_is_reduced(&1),
/// true
/// );
/// ```
#[inline]
fn mod_is_reduced(&self, m: &T) -> bool {
assert_ne!(*m, T::ZERO);
self.to_height() < *m
}
}