1 | /* -*- C++ -*- |
---|
2 | * |
---|
3 | * This file is a part of LEMON, a generic C++ optimization library |
---|
4 | * |
---|
5 | * Copyright (C) 2003-2007 |
---|
6 | * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
---|
7 | * (Egervary Research Group on Combinatorial Optimization, EGRES). |
---|
8 | * |
---|
9 | * Permission to use, modify and distribute this software is granted |
---|
10 | * provided that this copyright notice appears in all copies. For |
---|
11 | * precise terms see the accompanying LICENSE file. |
---|
12 | * |
---|
13 | * This software is provided "AS IS" with no warranty of any kind, |
---|
14 | * express or implied, and with no claim as to its suitability for any |
---|
15 | * purpose. |
---|
16 | * |
---|
17 | */ |
---|
18 | |
---|
19 | #ifndef LEMON_UNION_FIND_H |
---|
20 | #define LEMON_UNION_FIND_H |
---|
21 | |
---|
22 | //!\ingroup auxdat |
---|
23 | //!\file |
---|
24 | //!\brief Union-Find data structures. |
---|
25 | //! |
---|
26 | |
---|
27 | #include <vector> |
---|
28 | #include <list> |
---|
29 | #include <utility> |
---|
30 | #include <algorithm> |
---|
31 | |
---|
32 | #include <lemon/bits/invalid.h> |
---|
33 | |
---|
34 | namespace lemon { |
---|
35 | |
---|
36 | /// \ingroup auxdat |
---|
37 | /// |
---|
38 | /// \brief A \e Union-Find data structure implementation |
---|
39 | /// |
---|
40 | /// The class implements the \e Union-Find data structure. |
---|
41 | /// The union operation uses rank heuristic, while |
---|
42 | /// the find operation uses path compression. |
---|
43 | /// This is a very simple but efficient implementation, providing |
---|
44 | /// only four methods: join (union), find, insert and size. |
---|
45 | /// For more features see the \ref UnionFindEnum class. |
---|
46 | /// |
---|
47 | /// It is primarily used in Kruskal algorithm for finding minimal |
---|
48 | /// cost spanning tree in a graph. |
---|
49 | /// \sa kruskal() |
---|
50 | /// |
---|
51 | /// \pre You need to add all the elements by the \ref insert() |
---|
52 | /// method. |
---|
53 | template <typename _ItemIntMap> |
---|
54 | class UnionFind { |
---|
55 | public: |
---|
56 | |
---|
57 | typedef _ItemIntMap ItemIntMap; |
---|
58 | typedef typename ItemIntMap::Key Item; |
---|
59 | |
---|
60 | private: |
---|
61 | // If the items vector stores negative value for an item then |
---|
62 | // that item is root item and it has -items[it] component size. |
---|
63 | // Else the items[it] contains the index of the parent. |
---|
64 | std::vector<int> items; |
---|
65 | ItemIntMap& index; |
---|
66 | |
---|
67 | bool rep(int idx) const { |
---|
68 | return items[idx] < 0; |
---|
69 | } |
---|
70 | |
---|
71 | int repIndex(int idx) const { |
---|
72 | int k = idx; |
---|
73 | while (!rep(k)) { |
---|
74 | k = items[k] ; |
---|
75 | } |
---|
76 | while (idx != k) { |
---|
77 | int next = items[idx]; |
---|
78 | const_cast<int&>(items[idx]) = k; |
---|
79 | idx = next; |
---|
80 | } |
---|
81 | return k; |
---|
82 | } |
---|
83 | |
---|
84 | public: |
---|
85 | |
---|
86 | /// \brief Constructor |
---|
87 | /// |
---|
88 | /// Constructor of the UnionFind class. You should give an item to |
---|
89 | /// integer map which will be used from the data structure. If you |
---|
90 | /// modify directly this map that may cause segmentation fault, |
---|
91 | /// invalid data structure, or infinite loop when you use again |
---|
92 | /// the union-find. |
---|
93 | UnionFind(ItemIntMap& m) : index(m) {} |
---|
94 | |
---|
95 | /// \brief Returns the index of the element's component. |
---|
96 | /// |
---|
97 | /// The method returns the index of the element's component. |
---|
98 | /// This is an integer between zero and the number of inserted elements. |
---|
99 | /// |
---|
100 | int find(const Item& a) { |
---|
101 | return repIndex(index[a]); |
---|
102 | } |
---|
103 | |
---|
104 | /// \brief Clears the union-find data structure |
---|
105 | /// |
---|
106 | /// Erase each item from the data structure. |
---|
107 | void clear() { |
---|
108 | items.clear(); |
---|
109 | } |
---|
110 | |
---|
111 | /// \brief Inserts a new element into the structure. |
---|
112 | /// |
---|
113 | /// This method inserts a new element into the data structure. |
---|
114 | /// |
---|
115 | /// The method returns the index of the new component. |
---|
116 | int insert(const Item& a) { |
---|
117 | int n = items.size(); |
---|
118 | items.push_back(-1); |
---|
119 | index.set(a,n); |
---|
120 | return n; |
---|
121 | } |
---|
122 | |
---|
123 | /// \brief Joining the components of element \e a and element \e b. |
---|
124 | /// |
---|
125 | /// This is the \e union operation of the Union-Find structure. |
---|
126 | /// Joins the component of element \e a and component of |
---|
127 | /// element \e b. If \e a and \e b are in the same component then |
---|
128 | /// it returns false otherwise it returns true. |
---|
129 | bool join(const Item& a, const Item& b) { |
---|
130 | int ka = repIndex(index[a]); |
---|
131 | int kb = repIndex(index[b]); |
---|
132 | |
---|
133 | if ( ka == kb ) |
---|
134 | return false; |
---|
135 | |
---|
136 | if (items[ka] < items[kb]) { |
---|
137 | items[ka] += items[kb]; |
---|
138 | items[kb] = ka; |
---|
139 | } else { |
---|
140 | items[kb] += items[ka]; |
---|
141 | items[ka] = kb; |
---|
142 | } |
---|
143 | return true; |
---|
144 | } |
---|
145 | |
---|
146 | /// \brief Returns the size of the component of element \e a. |
---|
147 | /// |
---|
148 | /// Returns the size of the component of element \e a. |
---|
149 | int size(const Item& a) { |
---|
150 | int k = repIndex(index[a]); |
---|
151 | return - items[k]; |
---|
152 | } |
---|
153 | |
---|
154 | }; |
---|
155 | |
---|
156 | /// \ingroup auxdat |
---|
157 | /// |
---|
158 | /// \brief A \e Union-Find data structure implementation which |
---|
159 | /// is able to enumerate the components. |
---|
160 | /// |
---|
161 | /// The class implements a \e Union-Find data structure |
---|
162 | /// which is able to enumerate the components and the items in |
---|
163 | /// a component. If you don't need this feature then perhaps it's |
---|
164 | /// better to use the \ref UnionFind class which is more efficient. |
---|
165 | /// |
---|
166 | /// The union operation uses rank heuristic, while |
---|
167 | /// the find operation uses path compression. |
---|
168 | /// |
---|
169 | /// \pre You need to add all the elements by the \ref insert() |
---|
170 | /// method. |
---|
171 | /// |
---|
172 | template <typename _ItemIntMap> |
---|
173 | class UnionFindEnum { |
---|
174 | public: |
---|
175 | |
---|
176 | typedef _ItemIntMap ItemIntMap; |
---|
177 | typedef typename ItemIntMap::Key Item; |
---|
178 | |
---|
179 | private: |
---|
180 | |
---|
181 | ItemIntMap& index; |
---|
182 | |
---|
183 | // If the parent stores negative value for an item then that item |
---|
184 | // is root item and it has ~(items[it].parent) component id. Else |
---|
185 | // the items[it].parent contains the index of the parent. |
---|
186 | // |
---|
187 | // The \c next and \c prev provides the double-linked |
---|
188 | // cyclic list of one component's items. |
---|
189 | struct ItemT { |
---|
190 | int parent; |
---|
191 | Item item; |
---|
192 | |
---|
193 | int next, prev; |
---|
194 | }; |
---|
195 | |
---|
196 | std::vector<ItemT> items; |
---|
197 | int firstFreeItem; |
---|
198 | |
---|
199 | struct ClassT { |
---|
200 | int size; |
---|
201 | int firstItem; |
---|
202 | int next, prev; |
---|
203 | }; |
---|
204 | |
---|
205 | std::vector<ClassT> classes; |
---|
206 | int firstClass, firstFreeClass; |
---|
207 | |
---|
208 | int newClass() { |
---|
209 | if (firstFreeClass == -1) { |
---|
210 | int cdx = classes.size(); |
---|
211 | classes.push_back(ClassT()); |
---|
212 | return cdx; |
---|
213 | } else { |
---|
214 | int cdx = firstFreeClass; |
---|
215 | firstFreeClass = classes[firstFreeClass].next; |
---|
216 | return cdx; |
---|
217 | } |
---|
218 | } |
---|
219 | |
---|
220 | int newItem() { |
---|
221 | if (firstFreeItem == -1) { |
---|
222 | int idx = items.size(); |
---|
223 | items.push_back(ItemT()); |
---|
224 | return idx; |
---|
225 | } else { |
---|
226 | int idx = firstFreeItem; |
---|
227 | firstFreeItem = items[firstFreeItem].next; |
---|
228 | return idx; |
---|
229 | } |
---|
230 | } |
---|
231 | |
---|
232 | |
---|
233 | bool rep(int idx) const { |
---|
234 | return items[idx].parent < 0; |
---|
235 | } |
---|
236 | |
---|
237 | int repIndex(int idx) const { |
---|
238 | int k = idx; |
---|
239 | while (!rep(k)) { |
---|
240 | k = items[k].parent; |
---|
241 | } |
---|
242 | while (idx != k) { |
---|
243 | int next = items[idx].parent; |
---|
244 | const_cast<int&>(items[idx].parent) = k; |
---|
245 | idx = next; |
---|
246 | } |
---|
247 | return k; |
---|
248 | } |
---|
249 | |
---|
250 | int classIndex(int idx) const { |
---|
251 | return ~(items[repIndex(idx)].parent); |
---|
252 | } |
---|
253 | |
---|
254 | void singletonItem(int idx) { |
---|
255 | items[idx].next = idx; |
---|
256 | items[idx].prev = idx; |
---|
257 | } |
---|
258 | |
---|
259 | void laceItem(int idx, int rdx) { |
---|
260 | items[idx].prev = rdx; |
---|
261 | items[idx].next = items[rdx].next; |
---|
262 | items[items[rdx].next].prev = idx; |
---|
263 | items[rdx].next = idx; |
---|
264 | } |
---|
265 | |
---|
266 | void unlaceItem(int idx) { |
---|
267 | items[items[idx].prev].next = items[idx].next; |
---|
268 | items[items[idx].next].prev = items[idx].prev; |
---|
269 | |
---|
270 | items[idx].next = firstFreeItem; |
---|
271 | firstFreeItem = idx; |
---|
272 | } |
---|
273 | |
---|
274 | void spliceItems(int ak, int bk) { |
---|
275 | items[items[ak].prev].next = bk; |
---|
276 | items[items[bk].prev].next = ak; |
---|
277 | int tmp = items[ak].prev; |
---|
278 | items[ak].prev = items[bk].prev; |
---|
279 | items[bk].prev = tmp; |
---|
280 | |
---|
281 | } |
---|
282 | |
---|
283 | void laceClass(int cls) { |
---|
284 | if (firstClass != -1) { |
---|
285 | classes[firstClass].prev = cls; |
---|
286 | } |
---|
287 | classes[cls].next = firstClass; |
---|
288 | classes[cls].prev = -1; |
---|
289 | firstClass = cls; |
---|
290 | } |
---|
291 | |
---|
292 | void unlaceClass(int cls) { |
---|
293 | if (classes[cls].prev != -1) { |
---|
294 | classes[classes[cls].prev].next = classes[cls].next; |
---|
295 | } else { |
---|
296 | firstClass = classes[cls].next; |
---|
297 | } |
---|
298 | if (classes[cls].next != -1) { |
---|
299 | classes[classes[cls].next].prev = classes[cls].prev; |
---|
300 | } |
---|
301 | |
---|
302 | classes[cls].next = firstFreeClass; |
---|
303 | firstFreeClass = cls; |
---|
304 | } |
---|
305 | |
---|
306 | public: |
---|
307 | |
---|
308 | UnionFindEnum(ItemIntMap& _index) |
---|
309 | : index(_index), items(), firstFreeItem(-1), |
---|
310 | firstClass(-1), firstFreeClass(-1) {} |
---|
311 | |
---|
312 | /// \brief Inserts the given element into a new component. |
---|
313 | /// |
---|
314 | /// This method creates a new component consisting only of the |
---|
315 | /// given element. |
---|
316 | /// |
---|
317 | int insert(const Item& item) { |
---|
318 | int idx = newItem(); |
---|
319 | |
---|
320 | index.set(item, idx); |
---|
321 | |
---|
322 | singletonItem(idx); |
---|
323 | items[idx].item = item; |
---|
324 | |
---|
325 | int cdx = newClass(); |
---|
326 | |
---|
327 | items[idx].parent = ~cdx; |
---|
328 | |
---|
329 | laceClass(cdx); |
---|
330 | classes[cdx].size = 1; |
---|
331 | classes[cdx].firstItem = idx; |
---|
332 | |
---|
333 | firstClass = cdx; |
---|
334 | |
---|
335 | return cdx; |
---|
336 | } |
---|
337 | |
---|
338 | /// \brief Inserts the given element into the component of the others. |
---|
339 | /// |
---|
340 | /// This methods inserts the element \e a into the component of the |
---|
341 | /// element \e comp. |
---|
342 | void insert(const Item& item, int cls) { |
---|
343 | int rdx = classes[cls].firstItem; |
---|
344 | int idx = newItem(); |
---|
345 | |
---|
346 | index.set(item, idx); |
---|
347 | |
---|
348 | laceItem(idx, rdx); |
---|
349 | |
---|
350 | items[idx].item = item; |
---|
351 | items[idx].parent = rdx; |
---|
352 | |
---|
353 | ++classes[~(items[rdx].parent)].size; |
---|
354 | } |
---|
355 | |
---|
356 | /// \brief Clears the union-find data structure |
---|
357 | /// |
---|
358 | /// Erase each item from the data structure. |
---|
359 | void clear() { |
---|
360 | items.clear(); |
---|
361 | firstClass = -1; |
---|
362 | firstFreeItem = -1; |
---|
363 | } |
---|
364 | |
---|
365 | /// \brief Finds the component of the given element. |
---|
366 | /// |
---|
367 | /// The method returns the component id of the given element. |
---|
368 | int find(const Item &item) const { |
---|
369 | return ~(items[repIndex(index[item])].parent); |
---|
370 | } |
---|
371 | |
---|
372 | /// \brief Joining the component of element \e a and element \e b. |
---|
373 | /// |
---|
374 | /// This is the \e union operation of the Union-Find structure. |
---|
375 | /// Joins the component of element \e a and component of |
---|
376 | /// element \e b. If \e a and \e b are in the same component then |
---|
377 | /// returns -1 else returns the remaining class. |
---|
378 | int join(const Item& a, const Item& b) { |
---|
379 | |
---|
380 | int ak = repIndex(index[a]); |
---|
381 | int bk = repIndex(index[b]); |
---|
382 | |
---|
383 | if (ak == bk) { |
---|
384 | return -1; |
---|
385 | } |
---|
386 | |
---|
387 | int acx = ~(items[ak].parent); |
---|
388 | int bcx = ~(items[bk].parent); |
---|
389 | |
---|
390 | int rcx; |
---|
391 | |
---|
392 | if (classes[acx].size > classes[bcx].size) { |
---|
393 | classes[acx].size += classes[bcx].size; |
---|
394 | items[bk].parent = ak; |
---|
395 | unlaceClass(bcx); |
---|
396 | rcx = acx; |
---|
397 | } else { |
---|
398 | classes[bcx].size += classes[acx].size; |
---|
399 | items[ak].parent = bk; |
---|
400 | unlaceClass(acx); |
---|
401 | rcx = bcx; |
---|
402 | } |
---|
403 | spliceItems(ak, bk); |
---|
404 | |
---|
405 | return rcx; |
---|
406 | } |
---|
407 | |
---|
408 | /// \brief Returns the size of the class. |
---|
409 | /// |
---|
410 | /// Returns the size of the class. |
---|
411 | int size(int cls) const { |
---|
412 | return classes[cls].size; |
---|
413 | } |
---|
414 | |
---|
415 | /// \brief Splits up the component. |
---|
416 | /// |
---|
417 | /// Splitting the component into singleton components (component |
---|
418 | /// of size one). |
---|
419 | void split(int cls) { |
---|
420 | int fdx = classes[cls].firstItem; |
---|
421 | int idx = items[fdx].next; |
---|
422 | while (idx != fdx) { |
---|
423 | int next = items[idx].next; |
---|
424 | |
---|
425 | singletonItem(idx); |
---|
426 | |
---|
427 | int cdx = newClass(); |
---|
428 | items[idx].parent = ~cdx; |
---|
429 | |
---|
430 | laceClass(cdx); |
---|
431 | classes[cdx].size = 1; |
---|
432 | classes[cdx].firstItem = idx; |
---|
433 | |
---|
434 | idx = next; |
---|
435 | } |
---|
436 | |
---|
437 | items[idx].prev = idx; |
---|
438 | items[idx].next = idx; |
---|
439 | |
---|
440 | classes[~(items[idx].parent)].size = 1; |
---|
441 | |
---|
442 | } |
---|
443 | |
---|
444 | /// \brief Removes the given element from the structure. |
---|
445 | /// |
---|
446 | /// Removes the element from its component and if the component becomes |
---|
447 | /// empty then removes that component from the component list. |
---|
448 | /// |
---|
449 | /// \warning It is an error to remove an element which is not in |
---|
450 | /// the structure. |
---|
451 | /// \warning This running time of this operation is proportional to the |
---|
452 | /// number of the items in this class. |
---|
453 | void erase(const Item& item) { |
---|
454 | int idx = index[item]; |
---|
455 | int fdx = items[idx].next; |
---|
456 | |
---|
457 | int cdx = classIndex(idx); |
---|
458 | if (idx == fdx) { |
---|
459 | unlaceClass(cdx); |
---|
460 | items[idx].next = firstFreeItem; |
---|
461 | firstFreeItem = idx; |
---|
462 | return; |
---|
463 | } else { |
---|
464 | classes[cdx].firstItem = fdx; |
---|
465 | --classes[cdx].size; |
---|
466 | items[fdx].parent = ~cdx; |
---|
467 | |
---|
468 | unlaceItem(idx); |
---|
469 | idx = items[fdx].next; |
---|
470 | while (idx != fdx) { |
---|
471 | items[idx].parent = fdx; |
---|
472 | idx = items[idx].next; |
---|
473 | } |
---|
474 | |
---|
475 | } |
---|
476 | |
---|
477 | } |
---|
478 | |
---|
479 | /// \brief Gives back a representant item of the component. |
---|
480 | /// |
---|
481 | /// Gives back a representant item of the component. |
---|
482 | Item item(int cls) const { |
---|
483 | return items[classes[cls].firstItem].item; |
---|
484 | } |
---|
485 | |
---|
486 | /// \brief Removes the component of the given element from the structure. |
---|
487 | /// |
---|
488 | /// Removes the component of the given element from the structure. |
---|
489 | /// |
---|
490 | /// \warning It is an error to give an element which is not in the |
---|
491 | /// structure. |
---|
492 | void eraseClass(int cls) { |
---|
493 | int fdx = classes[cls].firstItem; |
---|
494 | unlaceClass(cls); |
---|
495 | items[items[fdx].prev].next = firstFreeItem; |
---|
496 | firstFreeItem = fdx; |
---|
497 | } |
---|
498 | |
---|
499 | /// \brief Lemon style iterator for the representant items. |
---|
500 | /// |
---|
501 | /// ClassIt is a lemon style iterator for the components. It iterates |
---|
502 | /// on the ids of the classes. |
---|
503 | class ClassIt { |
---|
504 | public: |
---|
505 | /// \brief Constructor of the iterator |
---|
506 | /// |
---|
507 | /// Constructor of the iterator |
---|
508 | ClassIt(const UnionFindEnum& ufe) : unionFind(&ufe) { |
---|
509 | cdx = unionFind->firstClass; |
---|
510 | } |
---|
511 | |
---|
512 | /// \brief Constructor to get invalid iterator |
---|
513 | /// |
---|
514 | /// Constructor to get invalid iterator |
---|
515 | ClassIt(Invalid) : unionFind(0), cdx(-1) {} |
---|
516 | |
---|
517 | /// \brief Increment operator |
---|
518 | /// |
---|
519 | /// It steps to the next representant item. |
---|
520 | ClassIt& operator++() { |
---|
521 | cdx = unionFind->classes[cdx].next; |
---|
522 | return *this; |
---|
523 | } |
---|
524 | |
---|
525 | /// \brief Conversion operator |
---|
526 | /// |
---|
527 | /// It converts the iterator to the current representant item. |
---|
528 | operator int() const { |
---|
529 | return cdx; |
---|
530 | } |
---|
531 | |
---|
532 | /// \brief Equality operator |
---|
533 | /// |
---|
534 | /// Equality operator |
---|
535 | bool operator==(const ClassIt& i) { |
---|
536 | return i.cdx == cdx; |
---|
537 | } |
---|
538 | |
---|
539 | /// \brief Inequality operator |
---|
540 | /// |
---|
541 | /// Inequality operator |
---|
542 | bool operator!=(const ClassIt& i) { |
---|
543 | return i.cdx != cdx; |
---|
544 | } |
---|
545 | |
---|
546 | private: |
---|
547 | const UnionFindEnum* unionFind; |
---|
548 | int cdx; |
---|
549 | }; |
---|
550 | |
---|
551 | /// \brief Lemon style iterator for the items of a component. |
---|
552 | /// |
---|
553 | /// ClassIt is a lemon style iterator for the components. It iterates |
---|
554 | /// on the items of a class. By example if you want to iterate on |
---|
555 | /// each items of each classes then you may write the next code. |
---|
556 | ///\code |
---|
557 | /// for (ClassIt cit(ufe); cit != INVALID; ++cit) { |
---|
558 | /// std::cout << "Class: "; |
---|
559 | /// for (ItemIt iit(ufe, cit); iit != INVALID; ++iit) { |
---|
560 | /// std::cout << toString(iit) << ' ' << std::endl; |
---|
561 | /// } |
---|
562 | /// std::cout << std::endl; |
---|
563 | /// } |
---|
564 | ///\endcode |
---|
565 | class ItemIt { |
---|
566 | public: |
---|
567 | /// \brief Constructor of the iterator |
---|
568 | /// |
---|
569 | /// Constructor of the iterator. The iterator iterates |
---|
570 | /// on the class of the \c item. |
---|
571 | ItemIt(const UnionFindEnum& ufe, int cls) : unionFind(&ufe) { |
---|
572 | fdx = idx = unionFind->classes[cls].firstItem; |
---|
573 | } |
---|
574 | |
---|
575 | /// \brief Constructor to get invalid iterator |
---|
576 | /// |
---|
577 | /// Constructor to get invalid iterator |
---|
578 | ItemIt(Invalid) : unionFind(0), idx(-1) {} |
---|
579 | |
---|
580 | /// \brief Increment operator |
---|
581 | /// |
---|
582 | /// It steps to the next item in the class. |
---|
583 | ItemIt& operator++() { |
---|
584 | idx = unionFind->items[idx].next; |
---|
585 | if (idx == fdx) idx = -1; |
---|
586 | return *this; |
---|
587 | } |
---|
588 | |
---|
589 | /// \brief Conversion operator |
---|
590 | /// |
---|
591 | /// It converts the iterator to the current item. |
---|
592 | operator const Item&() const { |
---|
593 | return unionFind->items[idx].item; |
---|
594 | } |
---|
595 | |
---|
596 | /// \brief Equality operator |
---|
597 | /// |
---|
598 | /// Equality operator |
---|
599 | bool operator==(const ItemIt& i) { |
---|
600 | return i.idx == idx; |
---|
601 | } |
---|
602 | |
---|
603 | /// \brief Inequality operator |
---|
604 | /// |
---|
605 | /// Inequality operator |
---|
606 | bool operator!=(const ItemIt& i) { |
---|
607 | return i.idx != idx; |
---|
608 | } |
---|
609 | |
---|
610 | private: |
---|
611 | const UnionFindEnum* unionFind; |
---|
612 | int idx, fdx; |
---|
613 | }; |
---|
614 | |
---|
615 | }; |
---|
616 | |
---|
617 | /// \ingroup auxdat |
---|
618 | /// |
---|
619 | /// \brief A \e Extend-Find data structure implementation which |
---|
620 | /// is able to enumerate the components. |
---|
621 | /// |
---|
622 | /// The class implements an \e Extend-Find data structure which is |
---|
623 | /// able to enumerate the components and the items in a |
---|
624 | /// component. The data structure is a simplification of the |
---|
625 | /// Union-Find structure, and it does not allow to merge two components. |
---|
626 | /// |
---|
627 | /// \pre You need to add all the elements by the \ref insert() |
---|
628 | /// method. |
---|
629 | template <typename _ItemIntMap> |
---|
630 | class ExtendFindEnum { |
---|
631 | public: |
---|
632 | |
---|
633 | typedef _ItemIntMap ItemIntMap; |
---|
634 | typedef typename ItemIntMap::Key Item; |
---|
635 | |
---|
636 | private: |
---|
637 | |
---|
638 | ItemIntMap& index; |
---|
639 | |
---|
640 | struct ItemT { |
---|
641 | int cls; |
---|
642 | Item item; |
---|
643 | int next, prev; |
---|
644 | }; |
---|
645 | |
---|
646 | std::vector<ItemT> items; |
---|
647 | int firstFreeItem; |
---|
648 | |
---|
649 | struct ClassT { |
---|
650 | int firstItem; |
---|
651 | int next, prev; |
---|
652 | }; |
---|
653 | |
---|
654 | std::vector<ClassT> classes; |
---|
655 | |
---|
656 | int firstClass, firstFreeClass; |
---|
657 | |
---|
658 | int newClass() { |
---|
659 | if (firstFreeClass != -1) { |
---|
660 | int cdx = firstFreeClass; |
---|
661 | firstFreeClass = classes[cdx].next; |
---|
662 | return cdx; |
---|
663 | } else { |
---|
664 | classes.push_back(ClassT()); |
---|
665 | return classes.size() - 1; |
---|
666 | } |
---|
667 | } |
---|
668 | |
---|
669 | int newItem() { |
---|
670 | if (firstFreeItem != -1) { |
---|
671 | int idx = firstFreeItem; |
---|
672 | firstFreeItem = items[idx].next; |
---|
673 | return idx; |
---|
674 | } else { |
---|
675 | items.push_back(ItemT()); |
---|
676 | return items.size() - 1; |
---|
677 | } |
---|
678 | } |
---|
679 | |
---|
680 | public: |
---|
681 | |
---|
682 | /// \brief Constructor |
---|
683 | ExtendFindEnum(ItemIntMap& _index) |
---|
684 | : index(_index), items(), firstFreeItem(-1), |
---|
685 | classes(), firstClass(-1), firstFreeClass(-1) {} |
---|
686 | |
---|
687 | /// \brief Inserts the given element into a new component. |
---|
688 | /// |
---|
689 | /// This method creates a new component consisting only of the |
---|
690 | /// given element. |
---|
691 | int insert(const Item& item) { |
---|
692 | int cdx = newClass(); |
---|
693 | classes[cdx].prev = -1; |
---|
694 | classes[cdx].next = firstClass; |
---|
695 | if (firstClass != -1) { |
---|
696 | classes[firstClass].prev = cdx; |
---|
697 | } |
---|
698 | firstClass = cdx; |
---|
699 | |
---|
700 | int idx = newItem(); |
---|
701 | items[idx].item = item; |
---|
702 | items[idx].cls = cdx; |
---|
703 | items[idx].prev = idx; |
---|
704 | items[idx].next = idx; |
---|
705 | |
---|
706 | classes[cdx].firstItem = idx; |
---|
707 | |
---|
708 | index.set(item, idx); |
---|
709 | |
---|
710 | return cdx; |
---|
711 | } |
---|
712 | |
---|
713 | /// \brief Inserts the given element into the given component. |
---|
714 | /// |
---|
715 | /// This methods inserts the element \e item a into the \e cls class. |
---|
716 | void insert(const Item& item, int cls) { |
---|
717 | int idx = newItem(); |
---|
718 | int rdx = classes[cls].firstItem; |
---|
719 | items[idx].item = item; |
---|
720 | items[idx].cls = cls; |
---|
721 | |
---|
722 | items[idx].prev = rdx; |
---|
723 | items[idx].next = items[rdx].next; |
---|
724 | items[items[rdx].next].prev = idx; |
---|
725 | items[rdx].next = idx; |
---|
726 | |
---|
727 | index.set(item, idx); |
---|
728 | } |
---|
729 | |
---|
730 | /// \brief Clears the union-find data structure |
---|
731 | /// |
---|
732 | /// Erase each item from the data structure. |
---|
733 | void clear() { |
---|
734 | items.clear(); |
---|
735 | classes.clear; |
---|
736 | firstClass = firstFreeClass = firstFreeItem = -1; |
---|
737 | } |
---|
738 | |
---|
739 | /// \brief Gives back the class of the \e item. |
---|
740 | /// |
---|
741 | /// Gives back the class of the \e item. |
---|
742 | int find(const Item &item) const { |
---|
743 | return items[index[item]].cls; |
---|
744 | } |
---|
745 | |
---|
746 | /// \brief Gives back a representant item of the component. |
---|
747 | /// |
---|
748 | /// Gives back a representant item of the component. |
---|
749 | Item item(int cls) const { |
---|
750 | return items[classes[cls].firstItem].item; |
---|
751 | } |
---|
752 | |
---|
753 | /// \brief Removes the given element from the structure. |
---|
754 | /// |
---|
755 | /// Removes the element from its component and if the component becomes |
---|
756 | /// empty then removes that component from the component list. |
---|
757 | /// |
---|
758 | /// \warning It is an error to remove an element which is not in |
---|
759 | /// the structure. |
---|
760 | void erase(const Item &item) { |
---|
761 | int idx = index[item]; |
---|
762 | int cdx = items[idx].cls; |
---|
763 | |
---|
764 | if (idx == items[idx].next) { |
---|
765 | if (classes[cdx].prev != -1) { |
---|
766 | classes[classes[cdx].prev].next = classes[cdx].next; |
---|
767 | } else { |
---|
768 | firstClass = classes[cdx].next; |
---|
769 | } |
---|
770 | if (classes[cdx].next != -1) { |
---|
771 | classes[classes[cdx].next].prev = classes[cdx].prev; |
---|
772 | } |
---|
773 | classes[cdx].next = firstFreeClass; |
---|
774 | firstFreeClass = cdx; |
---|
775 | } else { |
---|
776 | classes[cdx].firstItem = items[idx].next; |
---|
777 | items[items[idx].next].prev = items[idx].prev; |
---|
778 | items[items[idx].prev].next = items[idx].next; |
---|
779 | } |
---|
780 | items[idx].next = firstFreeItem; |
---|
781 | firstFreeItem = idx; |
---|
782 | |
---|
783 | } |
---|
784 | |
---|
785 | |
---|
786 | /// \brief Removes the component of the given element from the structure. |
---|
787 | /// |
---|
788 | /// Removes the component of the given element from the structure. |
---|
789 | /// |
---|
790 | /// \warning It is an error to give an element which is not in the |
---|
791 | /// structure. |
---|
792 | void eraseClass(int cdx) { |
---|
793 | int idx = classes[cdx].firstItem; |
---|
794 | items[items[idx].prev].next = firstFreeItem; |
---|
795 | firstFreeItem = idx; |
---|
796 | |
---|
797 | if (classes[cdx].prev != -1) { |
---|
798 | classes[classes[cdx].prev].next = classes[cdx].next; |
---|
799 | } else { |
---|
800 | firstClass = classes[cdx].next; |
---|
801 | } |
---|
802 | if (classes[cdx].next != -1) { |
---|
803 | classes[classes[cdx].next].prev = classes[cdx].prev; |
---|
804 | } |
---|
805 | classes[cdx].next = firstFreeClass; |
---|
806 | firstFreeClass = cdx; |
---|
807 | } |
---|
808 | |
---|
809 | /// \brief Lemon style iterator for the classes. |
---|
810 | /// |
---|
811 | /// ClassIt is a lemon style iterator for the components. It iterates |
---|
812 | /// on the ids of classes. |
---|
813 | class ClassIt { |
---|
814 | public: |
---|
815 | /// \brief Constructor of the iterator |
---|
816 | /// |
---|
817 | /// Constructor of the iterator |
---|
818 | ClassIt(const ExtendFindEnum& ufe) : extendFind(&ufe) { |
---|
819 | cdx = extendFind->firstClass; |
---|
820 | } |
---|
821 | |
---|
822 | /// \brief Constructor to get invalid iterator |
---|
823 | /// |
---|
824 | /// Constructor to get invalid iterator |
---|
825 | ClassIt(Invalid) : extendFind(0), cdx(-1) {} |
---|
826 | |
---|
827 | /// \brief Increment operator |
---|
828 | /// |
---|
829 | /// It steps to the next representant item. |
---|
830 | ClassIt& operator++() { |
---|
831 | cdx = extendFind->classes[cdx].next; |
---|
832 | return *this; |
---|
833 | } |
---|
834 | |
---|
835 | /// \brief Conversion operator |
---|
836 | /// |
---|
837 | /// It converts the iterator to the current class id. |
---|
838 | operator int() const { |
---|
839 | return cdx; |
---|
840 | } |
---|
841 | |
---|
842 | /// \brief Equality operator |
---|
843 | /// |
---|
844 | /// Equality operator |
---|
845 | bool operator==(const ClassIt& i) { |
---|
846 | return i.cdx == cdx; |
---|
847 | } |
---|
848 | |
---|
849 | /// \brief Inequality operator |
---|
850 | /// |
---|
851 | /// Inequality operator |
---|
852 | bool operator!=(const ClassIt& i) { |
---|
853 | return i.cdx != cdx; |
---|
854 | } |
---|
855 | |
---|
856 | private: |
---|
857 | const ExtendFindEnum* extendFind; |
---|
858 | int cdx; |
---|
859 | }; |
---|
860 | |
---|
861 | /// \brief Lemon style iterator for the items of a component. |
---|
862 | /// |
---|
863 | /// ClassIt is a lemon style iterator for the components. It iterates |
---|
864 | /// on the items of a class. By example if you want to iterate on |
---|
865 | /// each items of each classes then you may write the next code. |
---|
866 | ///\code |
---|
867 | /// for (ClassIt cit(ufe); cit != INVALID; ++cit) { |
---|
868 | /// std::cout << "Class: "; |
---|
869 | /// for (ItemIt iit(ufe, cit); iit != INVALID; ++iit) { |
---|
870 | /// std::cout << toString(iit) << ' ' << std::endl; |
---|
871 | /// } |
---|
872 | /// std::cout << std::endl; |
---|
873 | /// } |
---|
874 | ///\endcode |
---|
875 | class ItemIt { |
---|
876 | public: |
---|
877 | /// \brief Constructor of the iterator |
---|
878 | /// |
---|
879 | /// Constructor of the iterator. The iterator iterates |
---|
880 | /// on the class of the \c item. |
---|
881 | ItemIt(const ExtendFindEnum& ufe, int cls) : extendFind(&ufe) { |
---|
882 | fdx = idx = extendFind->classes[cls].firstItem; |
---|
883 | } |
---|
884 | |
---|
885 | /// \brief Constructor to get invalid iterator |
---|
886 | /// |
---|
887 | /// Constructor to get invalid iterator |
---|
888 | ItemIt(Invalid) : extendFind(0), idx(-1) {} |
---|
889 | |
---|
890 | /// \brief Increment operator |
---|
891 | /// |
---|
892 | /// It steps to the next item in the class. |
---|
893 | ItemIt& operator++() { |
---|
894 | idx = extendFind->items[idx].next; |
---|
895 | if (fdx == idx) idx = -1; |
---|
896 | return *this; |
---|
897 | } |
---|
898 | |
---|
899 | /// \brief Conversion operator |
---|
900 | /// |
---|
901 | /// It converts the iterator to the current item. |
---|
902 | operator const Item&() const { |
---|
903 | return extendFind->items[idx].item; |
---|
904 | } |
---|
905 | |
---|
906 | /// \brief Equality operator |
---|
907 | /// |
---|
908 | /// Equality operator |
---|
909 | bool operator==(const ItemIt& i) { |
---|
910 | return i.idx == idx; |
---|
911 | } |
---|
912 | |
---|
913 | /// \brief Inequality operator |
---|
914 | /// |
---|
915 | /// Inequality operator |
---|
916 | bool operator!=(const ItemIt& i) { |
---|
917 | return i.idx != idx; |
---|
918 | } |
---|
919 | |
---|
920 | private: |
---|
921 | const ExtendFindEnum* extendFind; |
---|
922 | int idx, fdx; |
---|
923 | }; |
---|
924 | |
---|
925 | }; |
---|
926 | |
---|
927 | /// \ingroup auxdat |
---|
928 | /// |
---|
929 | /// \brief A \e Union-Find data structure implementation which |
---|
930 | /// is able to store a priority for each item and retrieve the minimum of |
---|
931 | /// each class. |
---|
932 | /// |
---|
933 | /// A \e Union-Find data structure implementation which is able to |
---|
934 | /// store a priority for each item and retrieve the minimum of each |
---|
935 | /// class. In addition, it supports the joining and splitting the |
---|
936 | /// components. If you don't need this feature then you makes |
---|
937 | /// better to use the \ref UnionFind class which is more efficient. |
---|
938 | /// |
---|
939 | /// The union-find data strcuture based on a (2, 16)-tree with a |
---|
940 | /// tournament minimum selection on the internal nodes. The insert |
---|
941 | /// operation takes O(1), the find, set, decrease and increase takes |
---|
942 | /// O(log(n)), where n is the number of nodes in the current |
---|
943 | /// component. The complexity of join and split is O(log(n)*k), |
---|
944 | /// where n is the sum of the number of the nodes and k is the |
---|
945 | /// number of joined components or the number of the components |
---|
946 | /// after the split. |
---|
947 | /// |
---|
948 | /// \pre You need to add all the elements by the \ref insert() |
---|
949 | /// method. |
---|
950 | /// |
---|
951 | template <typename _Value, typename _ItemIntMap, |
---|
952 | typename _Comp = std::less<_Value> > |
---|
953 | class HeapUnionFind { |
---|
954 | public: |
---|
955 | |
---|
956 | typedef _Value Value; |
---|
957 | typedef typename _ItemIntMap::Key Item; |
---|
958 | |
---|
959 | typedef _ItemIntMap ItemIntMap; |
---|
960 | |
---|
961 | typedef _Comp Comp; |
---|
962 | |
---|
963 | private: |
---|
964 | |
---|
965 | static const int cmax = 16; |
---|
966 | |
---|
967 | ItemIntMap& index; |
---|
968 | |
---|
969 | struct ClassNode { |
---|
970 | int parent; |
---|
971 | int depth; |
---|
972 | |
---|
973 | int left, right; |
---|
974 | int next, prev; |
---|
975 | }; |
---|
976 | |
---|
977 | int first_class; |
---|
978 | int first_free_class; |
---|
979 | std::vector<ClassNode> classes; |
---|
980 | |
---|
981 | int newClass() { |
---|
982 | if (first_free_class < 0) { |
---|
983 | int id = classes.size(); |
---|
984 | classes.push_back(ClassNode()); |
---|
985 | return id; |
---|
986 | } else { |
---|
987 | int id = first_free_class; |
---|
988 | first_free_class = classes[id].next; |
---|
989 | return id; |
---|
990 | } |
---|
991 | } |
---|
992 | |
---|
993 | void deleteClass(int id) { |
---|
994 | classes[id].next = first_free_class; |
---|
995 | first_free_class = id; |
---|
996 | } |
---|
997 | |
---|
998 | struct ItemNode { |
---|
999 | int parent; |
---|
1000 | Item item; |
---|
1001 | Value prio; |
---|
1002 | int next, prev; |
---|
1003 | int left, right; |
---|
1004 | int size; |
---|
1005 | }; |
---|
1006 | |
---|
1007 | int first_free_node; |
---|
1008 | std::vector<ItemNode> nodes; |
---|
1009 | |
---|
1010 | int newNode() { |
---|
1011 | if (first_free_node < 0) { |
---|
1012 | int id = nodes.size(); |
---|
1013 | nodes.push_back(ItemNode()); |
---|
1014 | return id; |
---|
1015 | } else { |
---|
1016 | int id = first_free_node; |
---|
1017 | first_free_node = nodes[id].next; |
---|
1018 | return id; |
---|
1019 | } |
---|
1020 | } |
---|
1021 | |
---|
1022 | void deleteNode(int id) { |
---|
1023 | nodes[id].next = first_free_node; |
---|
1024 | first_free_node = id; |
---|
1025 | } |
---|
1026 | |
---|
1027 | Comp comp; |
---|
1028 | |
---|
1029 | int findClass(int id) const { |
---|
1030 | int kd = id; |
---|
1031 | while (kd >= 0) { |
---|
1032 | kd = nodes[kd].parent; |
---|
1033 | } |
---|
1034 | return ~kd; |
---|
1035 | } |
---|
1036 | |
---|
1037 | int leftNode(int id) const { |
---|
1038 | int kd = ~(classes[id].parent); |
---|
1039 | for (int i = 0; i < classes[id].depth; ++i) { |
---|
1040 | kd = nodes[kd].left; |
---|
1041 | } |
---|
1042 | return kd; |
---|
1043 | } |
---|
1044 | |
---|
1045 | int nextNode(int id) const { |
---|
1046 | int depth = 0; |
---|
1047 | while (id >= 0 && nodes[id].next == -1) { |
---|
1048 | id = nodes[id].parent; |
---|
1049 | ++depth; |
---|
1050 | } |
---|
1051 | if (id < 0) { |
---|
1052 | return -1; |
---|
1053 | } |
---|
1054 | id = nodes[id].next; |
---|
1055 | while (depth--) { |
---|
1056 | id = nodes[id].left; |
---|
1057 | } |
---|
1058 | return id; |
---|
1059 | } |
---|
1060 | |
---|
1061 | |
---|
1062 | void setPrio(int id) { |
---|
1063 | int jd = nodes[id].left; |
---|
1064 | nodes[id].prio = nodes[jd].prio; |
---|
1065 | nodes[id].item = nodes[jd].item; |
---|
1066 | jd = nodes[jd].next; |
---|
1067 | while (jd != -1) { |
---|
1068 | if (comp(nodes[jd].prio, nodes[id].prio)) { |
---|
1069 | nodes[id].prio = nodes[jd].prio; |
---|
1070 | nodes[id].item = nodes[jd].item; |
---|
1071 | } |
---|
1072 | jd = nodes[jd].next; |
---|
1073 | } |
---|
1074 | } |
---|
1075 | |
---|
1076 | void push(int id, int jd) { |
---|
1077 | nodes[id].size = 1; |
---|
1078 | nodes[id].left = nodes[id].right = jd; |
---|
1079 | nodes[jd].next = nodes[jd].prev = -1; |
---|
1080 | nodes[jd].parent = id; |
---|
1081 | } |
---|
1082 | |
---|
1083 | void pushAfter(int id, int jd) { |
---|
1084 | int kd = nodes[id].parent; |
---|
1085 | if (nodes[id].next != -1) { |
---|
1086 | nodes[nodes[id].next].prev = jd; |
---|
1087 | if (kd >= 0) { |
---|
1088 | nodes[kd].size += 1; |
---|
1089 | } |
---|
1090 | } else { |
---|
1091 | if (kd >= 0) { |
---|
1092 | nodes[kd].right = jd; |
---|
1093 | nodes[kd].size += 1; |
---|
1094 | } |
---|
1095 | } |
---|
1096 | nodes[jd].next = nodes[id].next; |
---|
1097 | nodes[jd].prev = id; |
---|
1098 | nodes[id].next = jd; |
---|
1099 | nodes[jd].parent = kd; |
---|
1100 | } |
---|
1101 | |
---|
1102 | void pushRight(int id, int jd) { |
---|
1103 | nodes[id].size += 1; |
---|
1104 | nodes[jd].prev = nodes[id].right; |
---|
1105 | nodes[jd].next = -1; |
---|
1106 | nodes[nodes[id].right].next = jd; |
---|
1107 | nodes[id].right = jd; |
---|
1108 | nodes[jd].parent = id; |
---|
1109 | } |
---|
1110 | |
---|
1111 | void popRight(int id) { |
---|
1112 | nodes[id].size -= 1; |
---|
1113 | int jd = nodes[id].right; |
---|
1114 | nodes[nodes[jd].prev].next = -1; |
---|
1115 | nodes[id].right = nodes[jd].prev; |
---|
1116 | } |
---|
1117 | |
---|
1118 | void splice(int id, int jd) { |
---|
1119 | nodes[id].size += nodes[jd].size; |
---|
1120 | nodes[nodes[id].right].next = nodes[jd].left; |
---|
1121 | nodes[nodes[jd].left].prev = nodes[id].right; |
---|
1122 | int kd = nodes[jd].left; |
---|
1123 | while (kd != -1) { |
---|
1124 | nodes[kd].parent = id; |
---|
1125 | kd = nodes[kd].next; |
---|
1126 | } |
---|
1127 | nodes[id].right = nodes[jd].right; |
---|
1128 | } |
---|
1129 | |
---|
1130 | void split(int id, int jd) { |
---|
1131 | int kd = nodes[id].parent; |
---|
1132 | nodes[kd].right = nodes[id].prev; |
---|
1133 | nodes[nodes[id].prev].next = -1; |
---|
1134 | |
---|
1135 | nodes[jd].left = id; |
---|
1136 | nodes[id].prev = -1; |
---|
1137 | int num = 0; |
---|
1138 | while (id != -1) { |
---|
1139 | nodes[id].parent = jd; |
---|
1140 | nodes[jd].right = id; |
---|
1141 | id = nodes[id].next; |
---|
1142 | ++num; |
---|
1143 | } |
---|
1144 | nodes[kd].size -= num; |
---|
1145 | nodes[jd].size = num; |
---|
1146 | } |
---|
1147 | |
---|
1148 | void pushLeft(int id, int jd) { |
---|
1149 | nodes[id].size += 1; |
---|
1150 | nodes[jd].next = nodes[id].left; |
---|
1151 | nodes[jd].prev = -1; |
---|
1152 | nodes[nodes[id].left].prev = jd; |
---|
1153 | nodes[id].left = jd; |
---|
1154 | nodes[jd].parent = id; |
---|
1155 | } |
---|
1156 | |
---|
1157 | void popLeft(int id) { |
---|
1158 | nodes[id].size -= 1; |
---|
1159 | int jd = nodes[id].left; |
---|
1160 | nodes[nodes[jd].next].prev = -1; |
---|
1161 | nodes[id].left = nodes[jd].next; |
---|
1162 | } |
---|
1163 | |
---|
1164 | void repairLeft(int id) { |
---|
1165 | int jd = ~(classes[id].parent); |
---|
1166 | while (nodes[jd].left != -1) { |
---|
1167 | int kd = nodes[jd].left; |
---|
1168 | if (nodes[jd].size == 1) { |
---|
1169 | if (nodes[jd].parent < 0) { |
---|
1170 | classes[id].parent = ~kd; |
---|
1171 | classes[id].depth -= 1; |
---|
1172 | nodes[kd].parent = ~id; |
---|
1173 | deleteNode(jd); |
---|
1174 | jd = kd; |
---|
1175 | } else { |
---|
1176 | int pd = nodes[jd].parent; |
---|
1177 | if (nodes[nodes[jd].next].size < cmax) { |
---|
1178 | pushLeft(nodes[jd].next, nodes[jd].left); |
---|
1179 | if (less(nodes[jd].left, nodes[jd].next)) { |
---|
1180 | nodes[nodes[jd].next].prio = nodes[nodes[jd].left].prio; |
---|
1181 | nodes[nodes[jd].next].item = nodes[nodes[jd].left].item; |
---|
1182 | } |
---|
1183 | popLeft(pd); |
---|
1184 | deleteNode(jd); |
---|
1185 | jd = pd; |
---|
1186 | } else { |
---|
1187 | int ld = nodes[nodes[jd].next].left; |
---|
1188 | popLeft(nodes[jd].next); |
---|
1189 | pushRight(jd, ld); |
---|
1190 | if (less(ld, nodes[jd].left)) { |
---|
1191 | nodes[jd].item = nodes[ld].item; |
---|
1192 | nodes[jd].prio = nodes[jd].prio; |
---|
1193 | } |
---|
1194 | if (nodes[nodes[jd].next].item == nodes[ld].item) { |
---|
1195 | setPrio(nodes[jd].next); |
---|
1196 | } |
---|
1197 | jd = nodes[jd].left; |
---|
1198 | } |
---|
1199 | } |
---|
1200 | } else { |
---|
1201 | jd = nodes[jd].left; |
---|
1202 | } |
---|
1203 | } |
---|
1204 | } |
---|
1205 | |
---|
1206 | void repairRight(int id) { |
---|
1207 | int jd = ~(classes[id].parent); |
---|
1208 | while (nodes[jd].right != -1) { |
---|
1209 | int kd = nodes[jd].right; |
---|
1210 | if (nodes[jd].size == 1) { |
---|
1211 | if (nodes[jd].parent < 0) { |
---|
1212 | classes[id].parent = ~kd; |
---|
1213 | classes[id].depth -= 1; |
---|
1214 | nodes[kd].parent = ~id; |
---|
1215 | deleteNode(jd); |
---|
1216 | jd = kd; |
---|
1217 | } else { |
---|
1218 | int pd = nodes[jd].parent; |
---|
1219 | if (nodes[nodes[jd].prev].size < cmax) { |
---|
1220 | pushRight(nodes[jd].prev, nodes[jd].right); |
---|
1221 | if (less(nodes[jd].right, nodes[jd].prev)) { |
---|
1222 | nodes[nodes[jd].prev].prio = nodes[nodes[jd].right].prio; |
---|
1223 | nodes[nodes[jd].prev].item = nodes[nodes[jd].right].item; |
---|
1224 | } |
---|
1225 | popRight(pd); |
---|
1226 | deleteNode(jd); |
---|
1227 | jd = pd; |
---|
1228 | } else { |
---|
1229 | int ld = nodes[nodes[jd].prev].right; |
---|
1230 | popRight(nodes[jd].prev); |
---|
1231 | pushLeft(jd, ld); |
---|
1232 | if (less(ld, nodes[jd].right)) { |
---|
1233 | nodes[jd].item = nodes[ld].item; |
---|
1234 | nodes[jd].prio = nodes[jd].prio; |
---|
1235 | } |
---|
1236 | if (nodes[nodes[jd].prev].item == nodes[ld].item) { |
---|
1237 | setPrio(nodes[jd].prev); |
---|
1238 | } |
---|
1239 | jd = nodes[jd].right; |
---|
1240 | } |
---|
1241 | } |
---|
1242 | } else { |
---|
1243 | jd = nodes[jd].right; |
---|
1244 | } |
---|
1245 | } |
---|
1246 | } |
---|
1247 | |
---|
1248 | |
---|
1249 | bool less(int id, int jd) const { |
---|
1250 | return comp(nodes[id].prio, nodes[jd].prio); |
---|
1251 | } |
---|
1252 | |
---|
1253 | bool equal(int id, int jd) const { |
---|
1254 | return !less(id, jd) && !less(jd, id); |
---|
1255 | } |
---|
1256 | |
---|
1257 | |
---|
1258 | public: |
---|
1259 | |
---|
1260 | /// \brief Returns true when the given class is alive. |
---|
1261 | /// |
---|
1262 | /// Returns true when the given class is alive, ie. the class is |
---|
1263 | /// not nested into other class. |
---|
1264 | bool alive(int cls) const { |
---|
1265 | return classes[cls].parent < 0; |
---|
1266 | } |
---|
1267 | |
---|
1268 | /// \brief Returns true when the given class is trivial. |
---|
1269 | /// |
---|
1270 | /// Returns true when the given class is trivial, ie. the class |
---|
1271 | /// contains just one item directly. |
---|
1272 | bool trivial(int cls) const { |
---|
1273 | return classes[cls].left == -1; |
---|
1274 | } |
---|
1275 | |
---|
1276 | /// \brief Constructs the union-find. |
---|
1277 | /// |
---|
1278 | /// Constructs the union-find. |
---|
1279 | /// \brief _index The index map of the union-find. The data |
---|
1280 | /// structure uses internally for store references. |
---|
1281 | HeapUnionFind(ItemIntMap& _index) |
---|
1282 | : index(_index), first_class(-1), |
---|
1283 | first_free_class(-1), first_free_node(-1) {} |
---|
1284 | |
---|
1285 | /// \brief Insert a new node into a new component. |
---|
1286 | /// |
---|
1287 | /// Insert a new node into a new component. |
---|
1288 | /// \param item The item of the new node. |
---|
1289 | /// \param prio The priority of the new node. |
---|
1290 | /// \return The class id of the one-item-heap. |
---|
1291 | int insert(const Item& item, const Value& prio) { |
---|
1292 | int id = newNode(); |
---|
1293 | nodes[id].item = item; |
---|
1294 | nodes[id].prio = prio; |
---|
1295 | nodes[id].size = 0; |
---|
1296 | |
---|
1297 | nodes[id].prev = -1; |
---|
1298 | nodes[id].next = -1; |
---|
1299 | |
---|
1300 | nodes[id].left = -1; |
---|
1301 | nodes[id].right = -1; |
---|
1302 | |
---|
1303 | nodes[id].item = item; |
---|
1304 | index[item] = id; |
---|
1305 | |
---|
1306 | int class_id = newClass(); |
---|
1307 | classes[class_id].parent = ~id; |
---|
1308 | classes[class_id].depth = 0; |
---|
1309 | |
---|
1310 | classes[class_id].left = -1; |
---|
1311 | classes[class_id].right = -1; |
---|
1312 | |
---|
1313 | if (first_class != -1) { |
---|
1314 | classes[first_class].prev = class_id; |
---|
1315 | } |
---|
1316 | classes[class_id].next = first_class; |
---|
1317 | classes[class_id].prev = -1; |
---|
1318 | first_class = class_id; |
---|
1319 | |
---|
1320 | nodes[id].parent = ~class_id; |
---|
1321 | |
---|
1322 | return class_id; |
---|
1323 | } |
---|
1324 | |
---|
1325 | /// \brief The class of the item. |
---|
1326 | /// |
---|
1327 | /// \return The alive class id of the item, which is not nested into |
---|
1328 | /// other classes. |
---|
1329 | /// |
---|
1330 | /// The time complexity is O(log(n)). |
---|
1331 | int find(const Item& item) const { |
---|
1332 | return findClass(index[item]); |
---|
1333 | } |
---|
1334 | |
---|
1335 | /// \brief Joins the classes. |
---|
1336 | /// |
---|
1337 | /// The current function joins the given classes. The parameter is |
---|
1338 | /// an STL range which should be contains valid class ids. The |
---|
1339 | /// time complexity is O(log(n)*k) where n is the overall number |
---|
1340 | /// of the joined nodes and k is the number of classes. |
---|
1341 | /// \return The class of the joined classes. |
---|
1342 | /// \pre The range should contain at least two class ids. |
---|
1343 | template <typename Iterator> |
---|
1344 | int join(Iterator begin, Iterator end) { |
---|
1345 | std::vector<int> cs; |
---|
1346 | for (Iterator it = begin; it != end; ++it) { |
---|
1347 | cs.push_back(*it); |
---|
1348 | } |
---|
1349 | |
---|
1350 | int class_id = newClass(); |
---|
1351 | { // creation union-find |
---|
1352 | |
---|
1353 | if (first_class != -1) { |
---|
1354 | classes[first_class].prev = class_id; |
---|
1355 | } |
---|
1356 | classes[class_id].next = first_class; |
---|
1357 | classes[class_id].prev = -1; |
---|
1358 | first_class = class_id; |
---|
1359 | |
---|
1360 | classes[class_id].depth = classes[cs[0]].depth; |
---|
1361 | classes[class_id].parent = classes[cs[0]].parent; |
---|
1362 | nodes[~(classes[class_id].parent)].parent = ~class_id; |
---|
1363 | |
---|
1364 | int l = cs[0]; |
---|
1365 | |
---|
1366 | classes[class_id].left = l; |
---|
1367 | classes[class_id].right = l; |
---|
1368 | |
---|
1369 | if (classes[l].next != -1) { |
---|
1370 | classes[classes[l].next].prev = classes[l].prev; |
---|
1371 | } |
---|
1372 | classes[classes[l].prev].next = classes[l].next; |
---|
1373 | |
---|
1374 | classes[l].prev = -1; |
---|
1375 | classes[l].next = -1; |
---|
1376 | |
---|
1377 | classes[l].depth = leftNode(l); |
---|
1378 | classes[l].parent = class_id; |
---|
1379 | |
---|
1380 | } |
---|
1381 | |
---|
1382 | { // merging of heap |
---|
1383 | int l = class_id; |
---|
1384 | for (int ci = 1; ci < int(cs.size()); ++ci) { |
---|
1385 | int r = cs[ci]; |
---|
1386 | int rln = leftNode(r); |
---|
1387 | if (classes[l].depth > classes[r].depth) { |
---|
1388 | int id = ~(classes[l].parent); |
---|
1389 | for (int i = classes[r].depth + 1; i < classes[l].depth; ++i) { |
---|
1390 | id = nodes[id].right; |
---|
1391 | } |
---|
1392 | while (id >= 0 && nodes[id].size == cmax) { |
---|
1393 | int new_id = newNode(); |
---|
1394 | int right_id = nodes[id].right; |
---|
1395 | |
---|
1396 | popRight(id); |
---|
1397 | if (nodes[id].item == nodes[right_id].item) { |
---|
1398 | setPrio(id); |
---|
1399 | } |
---|
1400 | push(new_id, right_id); |
---|
1401 | pushRight(new_id, ~(classes[r].parent)); |
---|
1402 | setPrio(new_id); |
---|
1403 | |
---|
1404 | id = nodes[id].parent; |
---|
1405 | classes[r].parent = ~new_id; |
---|
1406 | } |
---|
1407 | if (id < 0) { |
---|
1408 | int new_parent = newNode(); |
---|
1409 | nodes[new_parent].next = -1; |
---|
1410 | nodes[new_parent].prev = -1; |
---|
1411 | nodes[new_parent].parent = ~l; |
---|
1412 | |
---|
1413 | push(new_parent, ~(classes[l].parent)); |
---|
1414 | pushRight(new_parent, ~(classes[r].parent)); |
---|
1415 | setPrio(new_parent); |
---|
1416 | |
---|
1417 | classes[l].parent = ~new_parent; |
---|
1418 | classes[l].depth += 1; |
---|
1419 | } else { |
---|
1420 | pushRight(id, ~(classes[r].parent)); |
---|
1421 | while (id >= 0 && less(~(classes[r].parent), id)) { |
---|
1422 | nodes[id].prio = nodes[~(classes[r].parent)].prio; |
---|
1423 | nodes[id].item = nodes[~(classes[r].parent)].item; |
---|
1424 | id = nodes[id].parent; |
---|
1425 | } |
---|
1426 | } |
---|
1427 | } else if (classes[r].depth > classes[l].depth) { |
---|
1428 | int id = ~(classes[r].parent); |
---|
1429 | for (int i = classes[l].depth + 1; i < classes[r].depth; ++i) { |
---|
1430 | id = nodes[id].left; |
---|
1431 | } |
---|
1432 | while (id >= 0 && nodes[id].size == cmax) { |
---|
1433 | int new_id = newNode(); |
---|
1434 | int left_id = nodes[id].left; |
---|
1435 | |
---|
1436 | popLeft(id); |
---|
1437 | if (nodes[id].prio == nodes[left_id].prio) { |
---|
1438 | setPrio(id); |
---|
1439 | } |
---|
1440 | push(new_id, left_id); |
---|
1441 | pushLeft(new_id, ~(classes[l].parent)); |
---|
1442 | setPrio(new_id); |
---|
1443 | |
---|
1444 | id = nodes[id].parent; |
---|
1445 | classes[l].parent = ~new_id; |
---|
1446 | |
---|
1447 | } |
---|
1448 | if (id < 0) { |
---|
1449 | int new_parent = newNode(); |
---|
1450 | nodes[new_parent].next = -1; |
---|
1451 | nodes[new_parent].prev = -1; |
---|
1452 | nodes[new_parent].parent = ~l; |
---|
1453 | |
---|
1454 | push(new_parent, ~(classes[r].parent)); |
---|
1455 | pushLeft(new_parent, ~(classes[l].parent)); |
---|
1456 | setPrio(new_parent); |
---|
1457 | |
---|
1458 | classes[r].parent = ~new_parent; |
---|
1459 | classes[r].depth += 1; |
---|
1460 | } else { |
---|
1461 | pushLeft(id, ~(classes[l].parent)); |
---|
1462 | while (id >= 0 && less(~(classes[l].parent), id)) { |
---|
1463 | nodes[id].prio = nodes[~(classes[l].parent)].prio; |
---|
1464 | nodes[id].item = nodes[~(classes[l].parent)].item; |
---|
1465 | id = nodes[id].parent; |
---|
1466 | } |
---|
1467 | } |
---|
1468 | nodes[~(classes[r].parent)].parent = ~l; |
---|
1469 | classes[l].parent = classes[r].parent; |
---|
1470 | classes[l].depth = classes[r].depth; |
---|
1471 | } else { |
---|
1472 | if (classes[l].depth != 0 && |
---|
1473 | nodes[~(classes[l].parent)].size + |
---|
1474 | nodes[~(classes[r].parent)].size <= cmax) { |
---|
1475 | splice(~(classes[l].parent), ~(classes[r].parent)); |
---|
1476 | deleteNode(~(classes[r].parent)); |
---|
1477 | if (less(~(classes[r].parent), ~(classes[l].parent))) { |
---|
1478 | nodes[~(classes[l].parent)].prio = |
---|
1479 | nodes[~(classes[r].parent)].prio; |
---|
1480 | nodes[~(classes[l].parent)].item = |
---|
1481 | nodes[~(classes[r].parent)].item; |
---|
1482 | } |
---|
1483 | } else { |
---|
1484 | int new_parent = newNode(); |
---|
1485 | nodes[new_parent].next = nodes[new_parent].prev = -1; |
---|
1486 | push(new_parent, ~(classes[l].parent)); |
---|
1487 | pushRight(new_parent, ~(classes[r].parent)); |
---|
1488 | setPrio(new_parent); |
---|
1489 | |
---|
1490 | classes[l].parent = ~new_parent; |
---|
1491 | classes[l].depth += 1; |
---|
1492 | nodes[new_parent].parent = ~l; |
---|
1493 | } |
---|
1494 | } |
---|
1495 | if (classes[r].next != -1) { |
---|
1496 | classes[classes[r].next].prev = classes[r].prev; |
---|
1497 | } |
---|
1498 | classes[classes[r].prev].next = classes[r].next; |
---|
1499 | |
---|
1500 | classes[r].prev = classes[l].right; |
---|
1501 | classes[classes[l].right].next = r; |
---|
1502 | classes[l].right = r; |
---|
1503 | classes[r].parent = l; |
---|
1504 | |
---|
1505 | classes[r].next = -1; |
---|
1506 | classes[r].depth = rln; |
---|
1507 | } |
---|
1508 | } |
---|
1509 | return class_id; |
---|
1510 | } |
---|
1511 | |
---|
1512 | /// \brief Split the class to subclasses. |
---|
1513 | /// |
---|
1514 | /// The current function splits the given class. The join, which |
---|
1515 | /// made the current class, stored a reference to the |
---|
1516 | /// subclasses. The \c splitClass() member restores the classes |
---|
1517 | /// and creates the heaps. The parameter is an STL output iterator |
---|
1518 | /// which will be filled with the subclass ids. The time |
---|
1519 | /// complexity is O(log(n)*k) where n is the overall number of |
---|
1520 | /// nodes in the splitted classes and k is the number of the |
---|
1521 | /// classes. |
---|
1522 | template <typename Iterator> |
---|
1523 | void split(int cls, Iterator out) { |
---|
1524 | std::vector<int> cs; |
---|
1525 | { // splitting union-find |
---|
1526 | int id = cls; |
---|
1527 | int l = classes[id].left; |
---|
1528 | |
---|
1529 | classes[l].parent = classes[id].parent; |
---|
1530 | classes[l].depth = classes[id].depth; |
---|
1531 | |
---|
1532 | nodes[~(classes[l].parent)].parent = ~l; |
---|
1533 | |
---|
1534 | *out++ = l; |
---|
1535 | |
---|
1536 | while (l != -1) { |
---|
1537 | cs.push_back(l); |
---|
1538 | l = classes[l].next; |
---|
1539 | } |
---|
1540 | |
---|
1541 | classes[classes[id].right].next = first_class; |
---|
1542 | classes[first_class].prev = classes[id].right; |
---|
1543 | first_class = classes[id].left; |
---|
1544 | |
---|
1545 | if (classes[id].next != -1) { |
---|
1546 | classes[classes[id].next].prev = classes[id].prev; |
---|
1547 | } |
---|
1548 | classes[classes[id].prev].next = classes[id].next; |
---|
1549 | |
---|
1550 | deleteClass(id); |
---|
1551 | } |
---|
1552 | |
---|
1553 | { |
---|
1554 | for (int i = 1; i < int(cs.size()); ++i) { |
---|
1555 | int l = classes[cs[i]].depth; |
---|
1556 | while (nodes[nodes[l].parent].left == l) { |
---|
1557 | l = nodes[l].parent; |
---|
1558 | } |
---|
1559 | int r = l; |
---|
1560 | while (nodes[l].parent >= 0) { |
---|
1561 | l = nodes[l].parent; |
---|
1562 | int new_node = newNode(); |
---|
1563 | |
---|
1564 | nodes[new_node].prev = -1; |
---|
1565 | nodes[new_node].next = -1; |
---|
1566 | |
---|
1567 | split(r, new_node); |
---|
1568 | pushAfter(l, new_node); |
---|
1569 | setPrio(l); |
---|
1570 | setPrio(new_node); |
---|
1571 | r = new_node; |
---|
1572 | } |
---|
1573 | classes[cs[i]].parent = ~r; |
---|
1574 | classes[cs[i]].depth = classes[~(nodes[l].parent)].depth; |
---|
1575 | nodes[r].parent = ~cs[i]; |
---|
1576 | |
---|
1577 | nodes[l].next = -1; |
---|
1578 | nodes[r].prev = -1; |
---|
1579 | |
---|
1580 | repairRight(~(nodes[l].parent)); |
---|
1581 | repairLeft(cs[i]); |
---|
1582 | |
---|
1583 | *out++ = cs[i]; |
---|
1584 | } |
---|
1585 | } |
---|
1586 | } |
---|
1587 | |
---|
1588 | /// \brief Gives back the priority of the current item. |
---|
1589 | /// |
---|
1590 | /// \return Gives back the priority of the current item. |
---|
1591 | const Value& operator[](const Item& item) const { |
---|
1592 | return nodes[index[item]].prio; |
---|
1593 | } |
---|
1594 | |
---|
1595 | /// \brief Sets the priority of the current item. |
---|
1596 | /// |
---|
1597 | /// Sets the priority of the current item. |
---|
1598 | void set(const Item& item, const Value& prio) { |
---|
1599 | if (comp(prio, nodes[index[item]].prio)) { |
---|
1600 | decrease(item, prio); |
---|
1601 | } else if (!comp(prio, nodes[index[item]].prio)) { |
---|
1602 | increase(item, prio); |
---|
1603 | } |
---|
1604 | } |
---|
1605 | |
---|
1606 | /// \brief Increase the priority of the current item. |
---|
1607 | /// |
---|
1608 | /// Increase the priority of the current item. |
---|
1609 | void increase(const Item& item, const Value& prio) { |
---|
1610 | int id = index[item]; |
---|
1611 | int kd = nodes[id].parent; |
---|
1612 | nodes[id].prio = prio; |
---|
1613 | while (kd >= 0 && nodes[kd].item == item) { |
---|
1614 | setPrio(kd); |
---|
1615 | kd = nodes[kd].parent; |
---|
1616 | } |
---|
1617 | } |
---|
1618 | |
---|
1619 | /// \brief Increase the priority of the current item. |
---|
1620 | /// |
---|
1621 | /// Increase the priority of the current item. |
---|
1622 | void decrease(const Item& item, const Value& prio) { |
---|
1623 | int id = index[item]; |
---|
1624 | int kd = nodes[id].parent; |
---|
1625 | nodes[id].prio = prio; |
---|
1626 | while (kd >= 0 && less(id, kd)) { |
---|
1627 | nodes[kd].prio = prio; |
---|
1628 | nodes[kd].item = item; |
---|
1629 | kd = nodes[kd].parent; |
---|
1630 | } |
---|
1631 | } |
---|
1632 | |
---|
1633 | /// \brief Gives back the minimum priority of the class. |
---|
1634 | /// |
---|
1635 | /// \return Gives back the minimum priority of the class. |
---|
1636 | const Value& classPrio(int cls) const { |
---|
1637 | return nodes[~(classes[cls].parent)].prio; |
---|
1638 | } |
---|
1639 | |
---|
1640 | /// \brief Gives back the minimum priority item of the class. |
---|
1641 | /// |
---|
1642 | /// \return Gives back the minimum priority item of the class. |
---|
1643 | const Item& classTop(int cls) const { |
---|
1644 | return nodes[~(classes[cls].parent)].item; |
---|
1645 | } |
---|
1646 | |
---|
1647 | /// \brief Gives back a representant item of the class. |
---|
1648 | /// |
---|
1649 | /// The representant is indpendent from the priorities of the |
---|
1650 | /// items. |
---|
1651 | /// \return Gives back a representant item of the class. |
---|
1652 | const Item& classRep(int id) const { |
---|
1653 | int parent = classes[id].parent; |
---|
1654 | return nodes[parent >= 0 ? classes[id].depth : leftNode(id)].item; |
---|
1655 | } |
---|
1656 | |
---|
1657 | /// \brief Lemon style iterator for the items of a class. |
---|
1658 | /// |
---|
1659 | /// ClassIt is a lemon style iterator for the components. It iterates |
---|
1660 | /// on the items of a class. By example if you want to iterate on |
---|
1661 | /// each items of each classes then you may write the next code. |
---|
1662 | ///\code |
---|
1663 | /// for (ClassIt cit(huf); cit != INVALID; ++cit) { |
---|
1664 | /// std::cout << "Class: "; |
---|
1665 | /// for (ItemIt iit(huf, cit); iit != INVALID; ++iit) { |
---|
1666 | /// std::cout << toString(iit) << ' ' << std::endl; |
---|
1667 | /// } |
---|
1668 | /// std::cout << std::endl; |
---|
1669 | /// } |
---|
1670 | ///\endcode |
---|
1671 | class ItemIt { |
---|
1672 | private: |
---|
1673 | |
---|
1674 | const HeapUnionFind* _huf; |
---|
1675 | int _id, _lid; |
---|
1676 | |
---|
1677 | public: |
---|
1678 | |
---|
1679 | /// \brief Default constructor |
---|
1680 | /// |
---|
1681 | /// Default constructor |
---|
1682 | ItemIt() {} |
---|
1683 | |
---|
1684 | ItemIt(const HeapUnionFind& huf, int cls) : _huf(&huf) { |
---|
1685 | int id = cls; |
---|
1686 | int parent = _huf->classes[id].parent; |
---|
1687 | if (parent >= 0) { |
---|
1688 | _id = _huf->classes[id].depth; |
---|
1689 | if (_huf->classes[id].next != -1) { |
---|
1690 | _lid = _huf->classes[_huf->classes[id].next].depth; |
---|
1691 | } else { |
---|
1692 | _lid = -1; |
---|
1693 | } |
---|
1694 | } else { |
---|
1695 | _id = _huf->leftNode(id); |
---|
1696 | _lid = -1; |
---|
1697 | } |
---|
1698 | } |
---|
1699 | |
---|
1700 | /// \brief Increment operator |
---|
1701 | /// |
---|
1702 | /// It steps to the next item in the class. |
---|
1703 | ItemIt& operator++() { |
---|
1704 | _id = _huf->nextNode(_id); |
---|
1705 | return *this; |
---|
1706 | } |
---|
1707 | |
---|
1708 | /// \brief Conversion operator |
---|
1709 | /// |
---|
1710 | /// It converts the iterator to the current item. |
---|
1711 | operator const Item&() const { |
---|
1712 | return _huf->nodes[_id].item; |
---|
1713 | } |
---|
1714 | |
---|
1715 | /// \brief Equality operator |
---|
1716 | /// |
---|
1717 | /// Equality operator |
---|
1718 | bool operator==(const ItemIt& i) { |
---|
1719 | return i._id == _id; |
---|
1720 | } |
---|
1721 | |
---|
1722 | /// \brief Inequality operator |
---|
1723 | /// |
---|
1724 | /// Inequality operator |
---|
1725 | bool operator!=(const ItemIt& i) { |
---|
1726 | return i._id != _id; |
---|
1727 | } |
---|
1728 | |
---|
1729 | /// \brief Equality operator |
---|
1730 | /// |
---|
1731 | /// Equality operator |
---|
1732 | bool operator==(Invalid) { |
---|
1733 | return _id == _lid; |
---|
1734 | } |
---|
1735 | |
---|
1736 | /// \brief Inequality operator |
---|
1737 | /// |
---|
1738 | /// Inequality operator |
---|
1739 | bool operator!=(Invalid) { |
---|
1740 | return _id != _lid; |
---|
1741 | } |
---|
1742 | |
---|
1743 | }; |
---|
1744 | |
---|
1745 | /// \brief Class iterator |
---|
1746 | /// |
---|
1747 | /// The iterator stores |
---|
1748 | class ClassIt { |
---|
1749 | private: |
---|
1750 | |
---|
1751 | const HeapUnionFind* _huf; |
---|
1752 | int _id; |
---|
1753 | |
---|
1754 | public: |
---|
1755 | |
---|
1756 | ClassIt(const HeapUnionFind& huf) |
---|
1757 | : _huf(&huf), _id(huf.first_class) {} |
---|
1758 | |
---|
1759 | ClassIt(const HeapUnionFind& huf, int cls) |
---|
1760 | : _huf(&huf), _id(huf.classes[cls].left) {} |
---|
1761 | |
---|
1762 | ClassIt(Invalid) : _huf(0), _id(-1) {} |
---|
1763 | |
---|
1764 | const ClassIt& operator++() { |
---|
1765 | _id = _huf->classes[_id].next; |
---|
1766 | return *this; |
---|
1767 | } |
---|
1768 | |
---|
1769 | /// \brief Equality operator |
---|
1770 | /// |
---|
1771 | /// Equality operator |
---|
1772 | bool operator==(const ClassIt& i) { |
---|
1773 | return i._id == _id; |
---|
1774 | } |
---|
1775 | |
---|
1776 | /// \brief Inequality operator |
---|
1777 | /// |
---|
1778 | /// Inequality operator |
---|
1779 | bool operator!=(const ClassIt& i) { |
---|
1780 | return i._id != _id; |
---|
1781 | } |
---|
1782 | |
---|
1783 | operator int() const { |
---|
1784 | return _id; |
---|
1785 | } |
---|
1786 | |
---|
1787 | }; |
---|
1788 | |
---|
1789 | }; |
---|
1790 | |
---|
1791 | //! @} |
---|
1792 | |
---|
1793 | } //namespace lemon |
---|
1794 | |
---|
1795 | #endif //LEMON_UNION_FIND_H |
---|