1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
// 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::{
Content, ContentAndPrimitivePart, PrimitivePart, PrimitivePartAssign,
};
use crate::num::basic::unsigneds::PrimitiveUnsigned;
use crate::unsigned_vector::UnsignedVector;
// The GCD of the elements. It stops as soon as it reaches 1, since nothing can lower it further.
pub(crate) fn content<T: PrimitiveUnsigned>(coefficients: &[T]) -> T {
let mut gcd = T::ZERO;
for &c in coefficients {
gcd.gcd_assign(c);
if gcd == T::ONE {
break;
}
}
gcd
}
// Divides every element by the content, which divides each of them exactly.
pub(crate) fn divide_by_content<T: PrimitiveUnsigned>(coefficients: &mut [T], content: T) {
if content > T::ONE {
for c in coefficients {
c.div_exact_assign(content);
}
}
}
impl<T: PrimitiveUnsigned> Content for UnsignedVector<T> {
type Output = T;
/// Computes the content of an [`UnsignedVector`], the GCD of its elements, taking the vector by
/// value.
///
/// The content of the 0-dimensional vector, and of a vector of zeros, is zero. The GCD is taken
/// element by element, stopping early once it reaches 1.
///
/// $$
/// f(v) = \gcd(v_0, v_1, \ldots, v_{n-1}),
/// $$
///
/// where $n$ is the dimension of $v$.
///
/// # Worst-case complexity
/// $T(n) = O(n)$
///
/// $M(n) = O(1)$
///
/// where $T$ is time, $M$ is additional memory, and $n$ is `self.dimension()`.
///
/// # Examples
/// ```
/// use core::str::FromStr;
/// use malachite_base::num::arithmetic::traits::Content;
/// use malachite_base::unsigned_vector::UnsignedVector;
///
/// let v = UnsignedVector::<u8>::from_str("(6, 4, 10)").unwrap();
/// assert_eq!(v.content(), 2);
/// assert_eq!(UnsignedVector::<u8>::from_str("()").unwrap().content(), 0);
/// ```
///
/// This is equivalent to `_fmpz_vec_content` from `fmpz_vec/content.c`, FLINT 3.6.0.
#[inline]
fn content(self) -> T {
content(&self.elements)
}
}
impl<T: PrimitiveUnsigned> Content for &UnsignedVector<T> {
type Output = T;
/// Computes the content of an [`UnsignedVector`], the GCD of its elements, taking the vector by
/// reference.
///
/// The content of the 0-dimensional vector, and of a vector of zeros, is zero. The GCD is taken
/// element by element, stopping early once it reaches 1.
///
/// $$
/// f(v) = \gcd(v_0, v_1, \ldots, v_{n-1}),
/// $$
///
/// where $n$ is the dimension of $v$.
///
/// # Worst-case complexity
/// $T(n) = O(n)$
///
/// $M(n) = O(1)$
///
/// where $T$ is time, $M$ is additional memory, and $n$ is `self.dimension()`.
///
/// # Examples
/// ```
/// use core::str::FromStr;
/// use malachite_base::num::arithmetic::traits::Content;
/// use malachite_base::unsigned_vector::UnsignedVector;
///
/// let v = UnsignedVector::<u8>::from_str("(6, 4, 10)").unwrap();
/// assert_eq!((&v).content(), 2);
/// assert_eq!(
/// (&UnsignedVector::<u8>::from_str("(0, 0)").unwrap()).content(),
/// 0
/// );
/// ```
///
/// This is equivalent to `_fmpz_vec_content` from `fmpz_vec/content.c`, FLINT 3.6.0.
#[inline]
fn content(self) -> T {
content(&self.elements)
}
}
impl<T: PrimitiveUnsigned> PrimitivePart for UnsignedVector<T> {
type Output = Self;
/// Computes the primitive part of an [`UnsignedVector`], taking the vector by value.
///
/// This is the vector divided by its content. The elements are non-negative, so this is also
/// the [`CanonicalPrimitivePart`](crate::num::arithmetic::traits::CanonicalPrimitivePart).
///
/// $$
/// v = \operatorname{cont}(v) \operatorname{pp}(v).
/// $$
///
/// The primitive part of a vector of zeros is itself, keeping its dimension.
///
/// # Worst-case complexity
/// $T(n) = O(n)$
///
/// $M(n) = O(1)$
///
/// where $T$ is time, $M$ is additional memory, and $n$ is `self.dimension()`.
///
/// # Examples
/// ```
/// use core::str::FromStr;
/// use malachite_base::num::arithmetic::traits::PrimitivePart;
/// use malachite_base::unsigned_vector::UnsignedVector;
///
/// let v = UnsignedVector::<u8>::from_str("(6, 4, 10)").unwrap();
/// assert_eq!(v.primitive_part().to_string(), "(3, 2, 5)");
/// assert_eq!(
/// UnsignedVector::<u8>::from_str("(0, 0)")
/// .unwrap()
/// .primitive_part()
/// .to_string(),
/// "(0, 0)"
/// );
/// ```
#[inline]
fn primitive_part(mut self) -> Self {
self.primitive_part_assign();
self
}
}
impl<T: PrimitiveUnsigned> PrimitivePart for &UnsignedVector<T> {
type Output = UnsignedVector<T>;
/// Computes the primitive part of an [`UnsignedVector`], taking the vector by reference.
///
/// This is the vector divided by its content. The elements are non-negative, so this is also
/// the [`CanonicalPrimitivePart`](crate::num::arithmetic::traits::CanonicalPrimitivePart).
///
/// $$
/// v = \operatorname{cont}(v) \operatorname{pp}(v).
/// $$
///
/// The primitive part of a vector of zeros is itself, keeping its dimension.
///
/// # Worst-case complexity
/// $T(n) = O(n)$
///
/// $M(n) = O(n)$
///
/// where $T$ is time, $M$ is additional memory, and $n$ is `self.dimension()`.
///
/// # Examples
/// ```
/// use core::str::FromStr;
/// use malachite_base::num::arithmetic::traits::PrimitivePart;
/// use malachite_base::unsigned_vector::UnsignedVector;
///
/// let v = UnsignedVector::<u8>::from_str("(6, 4, 10)").unwrap();
/// assert_eq!((&v).primitive_part().to_string(), "(3, 2, 5)");
/// ```
#[inline]
fn primitive_part(self) -> UnsignedVector<T> {
let content = content(&self.elements);
let mut elements = self.elements.clone();
divide_by_content(&mut elements, content);
UnsignedVector { elements }
}
}
impl<T: PrimitiveUnsigned> PrimitivePartAssign for UnsignedVector<T> {
/// Replaces an [`UnsignedVector`] with its primitive part, the vector divided by its content.
///
/// See [`primitive_part`](PrimitivePart::primitive_part).
///
/// # Worst-case complexity
/// $T(n) = O(n)$
///
/// $M(n) = O(1)$
///
/// where $T$ is time, $M$ is additional memory, and $n$ is `self.dimension()`.
///
/// # Examples
/// ```
/// use core::str::FromStr;
/// use malachite_base::num::arithmetic::traits::PrimitivePartAssign;
/// use malachite_base::unsigned_vector::UnsignedVector;
///
/// let mut v = UnsignedVector::<u8>::from_str("(6, 4, 10)").unwrap();
/// v.primitive_part_assign();
/// assert_eq!(v.to_string(), "(3, 2, 5)");
/// ```
#[inline]
fn primitive_part_assign(&mut self) {
let content = content(&self.elements);
divide_by_content(&mut self.elements, content);
}
}
impl<T: PrimitiveUnsigned> ContentAndPrimitivePart for UnsignedVector<T> {
type Content = T;
type PrimitivePart = Self;
/// Computes the content and the primitive part of an [`UnsignedVector`] together, taking the
/// vector by value.
///
/// See [`content`](Content::content) and [`primitive_part`](PrimitivePart::primitive_part); the
/// content is found once rather than twice.
///
/// # Worst-case complexity
/// $T(n) = O(n)$
///
/// $M(n) = O(1)$
///
/// where $T$ is time, $M$ is additional memory, and $n$ is `self.dimension()`.
///
/// # Examples
/// ```
/// use core::str::FromStr;
/// use malachite_base::num::arithmetic::traits::ContentAndPrimitivePart;
/// use malachite_base::unsigned_vector::UnsignedVector;
///
/// let v = UnsignedVector::<u8>::from_str("(6, 4, 10)").unwrap();
/// let (content, primitive_part) = v.content_and_primitive_part();
/// assert_eq!(content, 2);
/// assert_eq!(primitive_part.to_string(), "(3, 2, 5)");
/// ```
#[inline]
fn content_and_primitive_part(mut self) -> (T, Self) {
let content = content(&self.elements);
divide_by_content(&mut self.elements, content);
(content, self)
}
}
impl<T: PrimitiveUnsigned> ContentAndPrimitivePart for &UnsignedVector<T> {
type Content = T;
type PrimitivePart = UnsignedVector<T>;
/// Computes the content and the primitive part of an [`UnsignedVector`] together, taking the
/// vector by reference.
///
/// See [`content`](Content::content) and [`primitive_part`](PrimitivePart::primitive_part); the
/// content is found once rather than twice.
///
/// # Worst-case complexity
/// $T(n) = O(n)$
///
/// $M(n) = O(n)$
///
/// where $T$ is time, $M$ is additional memory, and $n$ is `self.dimension()`.
///
/// # Examples
/// ```
/// use core::str::FromStr;
/// use malachite_base::num::arithmetic::traits::ContentAndPrimitivePart;
/// use malachite_base::unsigned_vector::UnsignedVector;
///
/// let v = UnsignedVector::<u8>::from_str("(6, 4, 10)").unwrap();
/// let (content, primitive_part) = (&v).content_and_primitive_part();
/// assert_eq!(content, 2);
/// assert_eq!(primitive_part.to_string(), "(3, 2, 5)");
/// ```
#[inline]
fn content_and_primitive_part(self) -> (T, UnsignedVector<T>) {
let content = content(&self.elements);
let mut elements = self.elements.clone();
divide_by_content(&mut elements, content);
(content, UnsignedVector { elements })
}
}