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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::{Mod, ModAssign};
use crate::num::basic::unsigneds::PrimitiveUnsigned;
use crate::unsigned_vector::UnsignedVector;
use core::ops::{Rem, RemAssign};
impl<T: PrimitiveUnsigned> Rem<T> for UnsignedVector<T> {
type Output = Self;
/// Divides every element of an [`UnsignedVector`] by a `T`, keeping the remainders, taking the
/// vector by value.
///
/// $v \\% m$ is the vector whose $i$th element is $v_i \\% m$. The dimension is unchanged:
/// unlike a polynomial, a vector keeps the elements that reduce to zero, so $(4, 3)$ modulo 4
/// is $(0, 3)$.
///
/// The result is reduced modulo $m$, which is to say that
/// [`mod_is_reduced`](crate::num::arithmetic::traits::ModIsReduced::mod_is_reduced) returns
/// `true` for it.
///
/// $$
/// f(v, m) = w, \\quad \text{where} \\quad w_i = v_i - m \left \lfloor \frac{v_i}{m}
/// \right \rfloor.
/// $$
///
/// # Worst-case complexity
/// $T(n) = O(n)$
///
/// $M(n) = O(1)$
///
/// where $T$ is time, $M$ is additional memory, and $n$ is `self.dimension()`.
///
/// # Panics
/// Panics if `m` is 0.
///
/// # Examples
/// ```
/// use core::str::FromStr;
/// use malachite_base::unsigned_vector::UnsignedVector;
///
/// let v = UnsignedVector::<u64>::from_str("(5, 4, 1)").unwrap();
/// assert_eq!((v % 3).to_string(), "(2, 1, 1)");
///
/// // An element that reduces to zero stays, so the dimension is unchanged.
/// let v = UnsignedVector::<u64>::from_str("(4, 3)").unwrap();
/// assert_eq!((v % 4).to_string(), "(0, 3)");
/// ```
#[inline]
fn rem(mut self, m: T) -> Self {
self %= m;
self
}
}
impl<T: PrimitiveUnsigned> Rem<T> for &UnsignedVector<T> {
type Output = UnsignedVector<T>;
/// Divides every element of an [`UnsignedVector`] by a `T`, keeping the remainders, taking the
/// vector by reference.
///
/// See the documentation for the [`Rem`] implementation on [`UnsignedVector`] that takes the
/// vector by value for details.
///
/// # Worst-case complexity
/// $T(n) = O(n)$
///
/// $M(n) = O(n)$
///
/// where $T$ is time, $M$ is additional memory, and $n$ is `self.dimension()`.
///
/// # Panics
/// Panics if `m` is 0.
///
/// # Examples
/// ```
/// use core::str::FromStr;
/// use malachite_base::unsigned_vector::UnsignedVector;
///
/// let v = UnsignedVector::<u64>::from_str("(5, 4, 1)").unwrap();
/// assert_eq!((&v % 3).to_string(), "(2, 1, 1)");
///
/// // An element that reduces to zero stays, so the dimension is unchanged.
/// let v = UnsignedVector::<u64>::from_str("(4, 3)").unwrap();
/// assert_eq!((&v % 4).to_string(), "(0, 3)");
/// // The vector is left alone.
/// assert_eq!(v.to_string(), "(4, 3)");
/// ```
fn rem(self, m: T) -> UnsignedVector<T> {
assert_ne!(m, T::ZERO, "division by zero");
UnsignedVector {
elements: self.elements.iter().map(|&x| x % m).collect(),
}
}
}
impl<T: PrimitiveUnsigned> RemAssign<T> for UnsignedVector<T> {
/// Divides every element of an [`UnsignedVector`] by a `T`, replacing each element by the
/// remainder.
///
/// See the documentation for the [`Rem`] implementation on [`UnsignedVector`] that takes the
/// vector by value for details.
///
/// # Worst-case complexity
/// $T(n) = O(n)$
///
/// $M(n) = O(1)$
///
/// where $T$ is time, $M$ is additional memory, and $n$ is `self.dimension()`.
///
/// # Panics
/// Panics if `m` is 0.
///
/// # Examples
/// ```
/// use core::str::FromStr;
/// use malachite_base::unsigned_vector::UnsignedVector;
///
/// let mut v = UnsignedVector::<u64>::from_str("(5, 4, 1)").unwrap();
/// v %= 3;
/// assert_eq!(v.to_string(), "(2, 1, 1)");
///
/// let mut v = UnsignedVector::<u64>::from_str("(4, 3)").unwrap();
/// v %= 4;
/// assert_eq!(v.to_string(), "(0, 3)");
/// ```
fn rem_assign(&mut self, m: T) {
assert_ne!(m, T::ZERO, "division by zero");
for x in &mut self.elements {
*x %= m;
}
}
}
impl<T: PrimitiveUnsigned> Mod<T> for UnsignedVector<T> {
type Output = Self;
/// Divides every element of an [`UnsignedVector`] by a `T`, keeping the remainders, taking the
/// vector by value.
///
/// An [`UnsignedVector`]'s elements are never negative, so this agrees with `%` everywhere; it
/// is the same operation under the name the mod-family traits use. See the documentation for
/// the [`Rem`] implementation on [`UnsignedVector`] that takes the vector by value for details.
///
/// # Worst-case complexity
/// $T(n) = O(n)$
///
/// $M(n) = O(1)$
///
/// where $T$ is time, $M$ is additional memory, and $n$ is `self.dimension()`.
///
/// # Panics
/// Panics if `m` is 0.
///
/// # Examples
/// ```
/// use core::str::FromStr;
/// use malachite_base::num::arithmetic::traits::Mod;
/// use malachite_base::unsigned_vector::UnsignedVector;
///
/// let v = UnsignedVector::<u64>::from_str("(4, 4, 5)").unwrap();
/// assert_eq!(v.mod_op(3).to_string(), "(1, 1, 2)");
/// ```
#[inline]
fn mod_op(self, m: T) -> Self {
self % m
}
}
impl<T: PrimitiveUnsigned> Mod<T> for &UnsignedVector<T> {
type Output = UnsignedVector<T>;
/// Divides every element of an [`UnsignedVector`] by a `T`, keeping the remainders, taking the
/// vector by reference.
///
/// An [`UnsignedVector`]'s elements are never negative, so this agrees with `%` everywhere; it
/// is the same operation under the name the mod-family traits use. See the documentation for
/// the [`Rem`] implementation on [`UnsignedVector`] that takes the vector by value for details.
///
/// # Worst-case complexity
/// $T(n) = O(n)$
///
/// $M(n) = O(n)$
///
/// where $T$ is time, $M$ is additional memory, and $n$ is `self.dimension()`.
///
/// # Panics
/// Panics if `m` is 0.
///
/// # Examples
/// ```
/// use core::str::FromStr;
/// use malachite_base::num::arithmetic::traits::Mod;
/// use malachite_base::unsigned_vector::UnsignedVector;
///
/// let v = UnsignedVector::<u64>::from_str("(4, 4, 5)").unwrap();
/// assert_eq!((&v).mod_op(3).to_string(), "(1, 1, 2)");
/// ```
#[inline]
fn mod_op(self, m: T) -> UnsignedVector<T> {
self % m
}
}
impl<T: PrimitiveUnsigned> ModAssign<T> for UnsignedVector<T> {
/// Divides every element of an [`UnsignedVector`] by a `T`, replacing each element by the
/// remainder.
///
/// An [`UnsignedVector`]'s elements are never negative, so this agrees with `%=` everywhere; it
/// is the same operation under the name the mod-family traits use. See the documentation for
/// the [`Rem`] implementation on [`UnsignedVector`] that takes the vector by value for details.
///
/// # Worst-case complexity
/// $T(n) = O(n)$
///
/// $M(n) = O(1)$
///
/// where $T$ is time, $M$ is additional memory, and $n$ is `self.dimension()`.
///
/// # Panics
/// Panics if `m` is 0.
///
/// # Examples
/// ```
/// use core::str::FromStr;
/// use malachite_base::num::arithmetic::traits::ModAssign;
/// use malachite_base::unsigned_vector::UnsignedVector;
///
/// let mut v = UnsignedVector::<u64>::from_str("(4, 4, 5)").unwrap();
/// v.mod_assign(3);
/// assert_eq!(v.to_string(), "(1, 1, 2)");
/// ```
#[inline]
fn mod_assign(&mut self, m: T) {
*self %= m;
}
}