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
|
/**
* Copyright © 2014 Mattias Andrée (maandree@member.fsf.org)
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef ALGO_ALGORITHMS_ARRAYS_SORTED_H
#define ALGO_ALGORITHMS_ARRAYS_SORTED_H
/* NB! This will not play nice if the placeholder `T` is
* not set to a type only containing [0-9A-Za-z_] (and $
* in GNU C). Therefore, with the exception of `char`,
* `short`, `int`, `long`, `float` and `double`, you
* should only use `typedef`:ed types. */
#include <stddef.h>
/**
* The order elements are sorted in.
*/
typedef enum algo_sorted_order
{
/**
The array is not sorted.
*/
UNORDERED,
/**
* The array is sorted in ascending (normal) order.
*/
ASCENDING_ORDER,
/**
* The array is sorted in descending (reverse normal) order.
*/
DESCENDING_ORDER,
/**
* All elements in the array are mutually equal or the array
* contains less than two elements. This is the bitwise OR of
* `ASCENDING_ORDER` and `DESCENDING_ORDER`.
*/
FLAT
} algo_sorted_order_t;
/**
* Gets whether an array is sorted and in which order it is sorted.
*
* `algo_make_implementation_of_is_sorted(T)` is used to make
* this function available for a particular data type `T`. And
* implementation without modifiers and attributes will be
* expanded. You may add `static`, `inline` and `__attribute__`
* before calling `algo_make_implementation_of_is_sorted(T)`.
*
* `algo_make_prototype_of_is_sorted(T)` is the prototype
* counterpart of `algo_make_implementation_of_is_sorted(T)`.
* It too is will not add any modifiers or attributes by
* default. It will neither add a semicolon at the end of
* the prototype.
*
* `algo_is_sorted(T)` is used to get the version of the
* function that supports the data type `T`.
* `&(algo_is_sorted(T))` gets the address of this function
* and `algo_is_sorted(T)(items, n)` calls the function.
*
* This function is pure, if you use GCC you should add
* `__attribute__((pure))` to its prototype.
*
* @param items The items to check if they are ordered.
* @param n The number of elements in `items`.
* @return The order elements are sorted in.
*/
//>fun () {
algo_sorted_order_t algo_is_sorted__##T(const T* restrict items, size_t n)
{
const T* end = items + n;
T last, cur;
algo_sorted_order_t order = FLAT;
if (n == 0)
return FLAT;
for (last = *items++; items != end; last = cur)
if (cur = *items++, last < cur)
{
if (order == FLAT) order = ASCENDING_ORDER;
else if (order == DESCENDING_ORDER) return UNORDERED;
}
else if (last > cur)
{
if (order == FLAT) order = DESCENDING_ORDER;
else if (order == ASCENDING_ORDER) return UNORDERED;
}
return order;
}
//>} ; . ../make_fun
/**
* Gets whether an array is sorted and in which order it is sorted.
*
* This variant of `algo_is_sorted` is suitable for
* non-numeric data.
*
* `algo_make_implementation_of_is_sorted_cmp(T)` is used to make
* this function available for a particular data type `T`. And
* implementation without modifiers and attributes will be
* expanded. You may add `static`, `inline` and `__attribute__`
* before calling `algo_make_implementation_of_is_sorted_cmp(T)`.
*
* `algo_make_prototype_of_is_sorted_cmp(T)` is the prototype
* counterpart of `algo_make_implementation_of_is_sorted_cmp(T)`.
* It too is will not add any modifiers or attributes by
* default. It will neither add a semicolon at the end of
* the prototype.
*
* `algo_is_sorted_cmp(T)` is used to get the version of the
* function that supports the data type `T`.
* `&(algo_is_sorted_cmp(T))` gets the address of this function
* and `algo_is_sorted_cmp(T)(items, n, cmp)` calls the function.
*
* This function is not pure because `cmp` is not necessarily pure.
*
* @param items The items to check if they are ordered.
* @param n The number of elements in `items`.
* @param cmp Function used to compare two items, it should return a
* negative value if its first parameter is the lesser, a
* positive value if its second parameter is the lesser
* and zero if the parameters are equal.
* @return The order elements are sorted in.
*/
//>fun () {
algo_sorted_order_t algo_is_sorted_cmp__##T(const T* restrict items, size_t n,
int (*cmp)(const T*, const T*))
{
const T* end = items + n;
T last, cur;
algo_sorted_order_t order = FLAT;
int comparison;
if (n == 0)
return FLAT;
for (last = *items++; items != end; last = cur)
{
comparison = cmp(last, cur = *items++);
if (comparison < 0)
{
if (order == FLAT) order = ASCENDING_ORDER;
else if (order == DESCENDING_ORDER) return UNORDERED;
}
else if (comparison > 0)
{
if (order == FLAT) order = DESCENDING_ORDER;
else if (order == ASCENDING_ORDER) return UNORDERED;
}
}
return order;
}
//>} ; . ../make_fun
/**
* Gets whether an array is sorted and in which order it is sorted.
*
* This variant of `algo_is_sorted_cmp` allows you to
* store data needed for the comparison in a thread-safe
* way. It is reentrant.
*
* `algo_make_implementation_of_is_sorted_cmp_r(T)` is used to make
* this function available for a particular data type `T`. And
* implementation without modifiers and attributes will be
* expanded. You may add `static`, `inline` and `__attribute__`
* before calling `algo_make_implementation_of_is_sorted_cmp_r(T)`.
*
* `algo_make_prototype_of_is_sorted_cmp_r(T)` is the prototype
* counterpart of `algo_make_implementation_of_is_sorted_cmp_r(T)`.
* It too is will not add any modifiers or attributes by
* default. It will neither add a semicolon at the end of
* the prototype.
*
* `algo_is_sorted_cmp_r(T)` is used to get the version of the
* function that supports the data type `T`.
* `&(algo_is_sorted_cmp_r(T))` gets the address of this function
* and `algo_is_sorted_cmp_r(T)(items, n, cmp)` calls the function.
*
* This function is not pure because `cmp` is not necessarily pure.
*
* @param items The items to check if they are ordered.
* @param n The number of elements in `items`.
* @param cmp Function used to compare two items, it should return a
* negative value if its first parameter is the lesser, a
* positive value if its second parameter is the lesser
* and zero if the parameters are equal. `data` will be
* input as `cmp`'s third argument.
* @param data Arbitrary data (may be `NULL`) to pass throught to `cmp`.
* and zero if the parameters are equal.
* @return The order elements are sorted in.
*/
//>fun () {
algo_sorted_order_t algo_is_sorted_cmp_r__##T(const T* restrict items, size_t n,
int (*cmp)(const T*, const T*, void*), void* data)
{
const T* end = items + n;
T last, cur;
algo_sorted_order_t order = FLAT;
int comparison;
if (n == 0)
return FLAT;
for (last = *items++; items != end; last = cur)
{
comparison = cmp(last, cur = *items++, data);
if (comparison < 0)
{
if (order == FLAT) order = ASCENDING_ORDER;
else if (order == DESCENDING_ORDER) return UNORDERED;
}
else if (comparison > 0)
{
if (order == FLAT) order = DESCENDING_ORDER;
else if (order == ASCENDING_ORDER) return UNORDERED;
}
}
return order;
}
//>} ; . ../make_fun
#endif
|
