this repo has no description
dekker.one
1/* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */
2/*
3 * Main authors:
4 * Christian Schulte <schulte@gecode.org>
5 *
6 * Copyright:
7 * Christian Schulte, 2004
8 *
9 * This file is part of Gecode, the generic constraint
10 * development environment:
11 * http://www.gecode.org
12 *
13 * Permission is hereby granted, free of charge, to any person obtaining
14 * a copy of this software and associated documentation files (the
15 * "Software"), to deal in the Software without restriction, including
16 * without limitation the rights to use, copy, modify, merge, publish,
17 * distribute, sublicense, and/or sell copies of the Software, and to
18 * permit persons to whom the Software is furnished to do so, subject to
19 * the following conditions:
20 *
21 * The above copyright notice and this permission notice shall be
22 * included in all copies or substantial portions of the Software.
23 *
24 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
25 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
26 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
27 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
28 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
29 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
30 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
31 *
32 */
33
34#include <algorithm>
35
36namespace Gecode { namespace Iter { namespace Ranges {
37
38 /**
39 * \brief Range iterator for computing intersection (binary)
40 *
41 * \ingroup FuncIterRanges
42 */
43 template<class I, class J>
44 class Inter : public MinMax {
45 protected:
46 /// First iterator
47 I i;
48 /// Second iterator
49 J j;
50 public:
51 /// \name Constructors and initialization
52 //@{
53 /// Default constructor
54 Inter(void);
55 /// Initialize with iterator \a i and \a j
56 Inter(I& i, J& j);
57 /// Initialize with iterator \a i and \a j
58 void init(I& i, J& j);
59 //@}
60
61 /// \name Iteration control
62 //@{
63 /// Move iterator to next range (if possible)
64 void operator ++(void);
65 //@}
66 };
67
68
69 /**
70 * \brief Range iterator for intersection of iterators
71 *
72 * \ingroup FuncIterRanges
73 */
74 class NaryInter : public RangeListIter {
75 protected:
76 /// Freelist
77 RangeList* f;
78 public:
79 /// \name Constructors and initialization
80 //@{
81 /// Default constructor
82 NaryInter(void);
83 /// Initialize with single iterator \a i
84 template<class I>
85 NaryInter(Region& r, I& i);
86 /// Initialize with iterators \a i and \a j
87 template<class I, class J>
88 NaryInter(Region& r, I& i, J& j);
89 /// Initialize with \a n iterators in \a i
90 template<class I>
91 NaryInter(Region& r, I* i, int n);
92 /// Initialize with single iterator \a i
93 template<class I>
94 void init(Region& r, I& i);
95 /// Initialize with iterators \a i and \a j
96 template<class I, class J>
97 void init(Region& r, I& i, J& j);
98 /// Initialize with \a n iterators in \a i
99 template<class I>
100 void init(Region& r, I* i, int n);
101 /// Add iterator \a i
102 template<class I>
103 void operator &=(I& i);
104 /// Assignment operator (both iterators must be allocated from the same region)
105 NaryInter& operator =(const NaryInter& m);
106 //@}
107 };
108
109
110
111 /*
112 * Binary intersection
113 *
114 */
115
116 template<class I, class J>
117 inline void
118 Inter<I,J>::operator ++(void) {
119 if (!i() || !j()) goto done;
120 do {
121 while (i() && (i.max() < j.min())) ++i;
122 if (!i()) goto done;
123 while (j() && (j.max() < i.min())) ++j;
124 if (!j()) goto done;
125 } while (i.max() < j.min());
126 // Now the intervals overlap: consume the smaller interval
127 ma = std::min(i.max(),j.max());
128 mi = std::max(i.min(),j.min());
129 if (i.max() < j.max()) ++i; else ++j;
130 return;
131 done:
132 finish();
133 }
134
135 template<class I, class J>
136 forceinline
137 Inter<I,J>::Inter(void) {}
138
139 template<class I, class J>
140 forceinline
141 Inter<I,J>::Inter(I& i0, J& j0)
142 : i(i0), j(j0) {
143 operator ++();
144 }
145
146 template<class I, class J>
147 forceinline void
148 Inter<I,J>::init(I& i0, J& j0) {
149 i = i0; j = j0;
150 operator ++();
151 }
152
153
154 /*
155 * Nary intersection
156 *
157 */
158
159 forceinline
160 NaryInter::NaryInter(void) {}
161
162 template<class I>
163 forceinline void
164 NaryInter::init(Region& r, I& i) {
165 RangeListIter::init(r);
166 f = nullptr;
167 set(copy(i));
168 }
169
170 template<class I, class J>
171 forceinline void
172 NaryInter::init(Region& r, I& i, J& j) {
173 RangeListIter::init(r);
174 f = nullptr;
175 RangeList* h;
176 RangeList** c = &h;
177 while (i() && j()) {
178 do {
179 while (i() && (i.max() < j.min())) ++i;
180 if (!i()) goto done;
181 while (j() && (j.max() < i.min())) ++j;
182 if (!j()) goto done;
183 } while (i.max() < j.min());
184 // Now the intervals overlap: consume the smaller interval
185 RangeList* t = range(std::max(i.min(),j.min()),
186 std::min(i.max(),j.max()));
187 *c = t; c = &t->next;
188 if (i.max() < j.max()) ++i; else ++j;
189 }
190 done:
191 *c = nullptr;
192 set(h);
193 }
194
195 template<class I>
196 forceinline void
197 NaryInter::init(Region& r, I* i, int n) {
198 RangeListIter::init(r);
199 f = nullptr;
200 if ((n > 0) && i[0]()) {
201 RangeList* h;
202 RangeList** c = &h;
203
204 int min = i[0].min();
205 while (i[0]()) {
206 // Initialize with last interval
207 int max = i[0].max();
208 // Intersect with all other intervals
209 restart:
210 for (int j=n; j--;) {
211 // Skip intervals that are too small
212 while (i[j]() && (i[j].max() < min))
213 ++i[j];
214 if (!i[j]())
215 goto done;
216 if (i[j].min() > max) {
217 min=i[j].min();
218 max=i[j].max();
219 goto restart;
220 }
221 // Now the intervals overlap
222 if (min < i[j].min())
223 min = i[j].min();
224 if (max > i[j].max())
225 max = i[j].max();
226 }
227 RangeList* t = range(min,max);
228 *c = t; c = &t->next;
229 // The next interval must be at least two elements away
230 min = max + 2;
231 }
232 done:
233 *c = nullptr;
234 set(h);
235 }
236 }
237
238 template<class I>
239 forceinline
240 NaryInter::NaryInter(Region& r, I& i) {
241 init(r, i);
242 }
243 template<class I, class J>
244 forceinline
245 NaryInter::NaryInter(Region& r, I& i, J& j) {
246 init(r, i, j);
247 }
248 template<class I>
249 forceinline
250 NaryInter::NaryInter(Region& r, I* i, int n) {
251 init(r, i, n);
252 }
253
254 template<class I>
255 forceinline void
256 NaryInter::operator &=(I& i) {
257 RangeList* j = get();
258 // The new rangelist
259 RangeList* h;
260 RangeList** c = &h;
261 while (i() && (j != nullptr)) {
262 do {
263 while (i() && (i.max() < j->min))
264 ++i;
265 if (!i()) goto done;
266 while ((j != nullptr) && (j->max < i.min())) {
267 RangeList* t = j->next;
268 j->next = f; f = j;
269 j = t;
270 }
271 if (j == nullptr) goto done;
272 } while (i.max() < j->min);
273 // Now the intervals overlap: consume the smaller interval
274 RangeList* t = range(std::max(i.min(),j->min),
275 std::min(i.max(),j->max),f);
276 *c = t; c = &t->next;
277 if (i.max() < j->max) {
278 ++i;
279 } else {
280 RangeList* tn = j->next;
281 j->next = f; f = j;
282 j = tn;
283 }
284 }
285 done:
286 // Put remaining elements into freelist
287 while (j != nullptr) {
288 RangeList* t = j->next;
289 j->next = f; f = j;
290 j = t;
291 }
292 *c = nullptr;
293 set(h);
294 }
295
296 forceinline NaryInter&
297 NaryInter::operator =(const NaryInter& m) {
298 f = nullptr;
299 return static_cast<NaryInter&>(RangeListIter::operator =(m));
300 }
301
302}}}
303
304// STATISTICS: iter-any
305