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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;
use crate::num::basic::unsigneds::PrimitiveUnsigned;
use crate::unsigned_polynomial::UnsignedPolynomial;
impl<T: PrimitiveUnsigned> Height for UnsignedPolynomial<T> {
type Output = T;
/// Returns the height of a [`UnsignedPolynomial`]: the largest of its coefficients.
///
/// The zero polynomial has no coefficients, and its height is 0.
///
/// $$
/// f(p) = H(p) = \max_i |p_i|.
/// $$
///
/// # 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.
///
/// # Examples
/// ```
/// use core::str::FromStr;
/// use malachite_base::num::arithmetic::traits::Height;
/// use malachite_base::unsigned_polynomial::UnsignedPolynomial;
///
/// assert_eq!(
/// UnsignedPolynomial::<u64>::from_str("x^2+3*x+2")
/// .unwrap()
/// .to_height(),
/// 3
/// );
/// assert_eq!(
/// UnsignedPolynomial::<u64>::from_str("x^100")
/// .unwrap()
/// .to_height(),
/// 1
/// );
/// assert_eq!(
/// UnsignedPolynomial::<u64>::from_str("0")
/// .unwrap()
/// .to_height(),
/// 0
/// );
/// ```
///
/// This is equivalent to `fmpz_poly_height` from `fmpz_poly/norms.c`, FLINT 3.6.0, for a
/// polynomial whose coefficients are all nonnegative.
#[inline]
fn to_height(&self) -> T {
self.coefficients_asc()
.iter()
.copied()
.max()
.unwrap_or(T::ZERO)
}
/// Returns the height of a [`UnsignedPolynomial`], taking it by value.
///
/// A [`u64`] is [`Copy`], so this is the same work as [`to_height`](Height::to_height); it is
/// here so that the two spellings agree across the types that implement [`Height`].
///
/// # 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.
///
/// # Examples
/// ```
/// use core::str::FromStr;
/// use malachite_base::num::arithmetic::traits::Height;
/// use malachite_base::unsigned_polynomial::UnsignedPolynomial;
///
/// assert_eq!(
/// UnsignedPolynomial::<u64>::from_str("x^2+3*x+2")
/// .unwrap()
/// .into_height(),
/// 3
/// );
/// assert_eq!(
/// UnsignedPolynomial::<u64>::from_str("0")
/// .unwrap()
/// .into_height(),
/// 0
/// );
/// ```
#[inline]
fn into_height(self) -> T {
self.to_height()
}
/// Returns the number of significant bits of the height of a [`UnsignedPolynomial`].
///
/// Since bit length is monotone, this is the largest of the coefficients' bit lengths, which is
/// the bit length of the largest coefficient.
///
/// # 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.
///
/// # Examples
/// ```
/// use core::str::FromStr;
/// use malachite_base::num::arithmetic::traits::Height;
/// use malachite_base::unsigned_polynomial::UnsignedPolynomial;
///
/// assert_eq!(
/// UnsignedPolynomial::<u64>::from_str("x^2+3*x+2")
/// .unwrap()
/// .height_significant_bits(),
/// 2
/// );
/// assert_eq!(
/// UnsignedPolynomial::<u64>::from_str("0")
/// .unwrap()
/// .height_significant_bits(),
/// 0
/// );
/// ```
#[inline]
fn height_significant_bits(&self) -> u64 {
self.to_height().significant_bits()
}
}