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@@ -18,59 +18,55 @@ |
18 | 18 |
|
19 | 19 |
#ifndef LEMON_BIN_HEAP_H |
20 | 20 |
#define LEMON_BIN_HEAP_H |
21 | 21 |
|
22 | 22 |
///\ingroup auxdat |
23 | 23 |
///\file |
24 |
///\brief Binary |
|
24 |
///\brief Binary heap implementation. |
|
25 | 25 |
|
26 | 26 |
#include <vector> |
27 | 27 |
#include <utility> |
28 | 28 |
#include <functional> |
29 | 29 |
|
30 | 30 |
namespace lemon { |
31 | 31 |
|
32 |
///\ingroup auxdat |
|
32 |
/// \ingroup auxdat |
|
33 | 33 |
/// |
34 |
///\brief |
|
34 |
/// \brief Binary heap data structure. |
|
35 | 35 |
/// |
36 |
///This class implements the \e binary \e heap data structure. |
|
36 |
/// This class implements the \e binary \e heap data structure. |
|
37 |
/// It fully conforms to the \ref concepts::Heap "heap concept". |
|
37 | 38 |
/// |
38 |
///A \e heap is a data structure for storing items with specified values |
|
39 |
///called \e priorities in such a way that finding the item with minimum |
|
40 |
///priority is efficient. \c CMP specifies the ordering of the priorities. |
|
41 |
///In a heap one can change the priority of an item, add or erase an |
|
42 |
///item, etc. |
|
43 |
/// |
|
44 |
///\tparam PR Type of the priority of the items. |
|
45 |
///\tparam IM A read and writable item map with int values, used internally |
|
46 |
///to handle the cross references. |
|
47 |
///\tparam CMP A functor class for the ordering of the priorities. |
|
48 |
///The default is \c std::less<PR>. |
|
49 |
/// |
|
50 |
///\sa FibHeap |
|
51 |
///\sa Dijkstra |
|
39 |
/// \tparam PR Type of the priorities of the items. |
|
40 |
/// \tparam IM A read-writable item map with \c int values, used |
|
41 |
/// internally to handle the cross references. |
|
42 |
/// \tparam CMP A functor class for comparing the priorities. |
|
43 |
/// The default is \c std::less<PR>. |
|
44 |
#ifdef DOXYGEN |
|
45 |
template <typename PR, typename IM, typename CMP> |
|
46 |
#else |
|
52 | 47 |
template <typename PR, typename IM, typename CMP = std::less<PR> > |
48 |
#endif |
|
53 | 49 |
class BinHeap { |
50 |
public: |
|
54 | 51 |
|
55 |
public: |
|
56 |
///\e |
|
52 |
/// Type of the item-int map. |
|
57 | 53 |
typedef IM ItemIntMap; |
58 |
/// |
|
54 |
/// Type of the priorities. |
|
59 | 55 |
typedef PR Prio; |
60 |
/// |
|
56 |
/// Type of the items stored in the heap. |
|
61 | 57 |
typedef typename ItemIntMap::Key Item; |
62 |
/// |
|
58 |
/// Type of the item-priority pairs. |
|
63 | 59 |
typedef std::pair<Item,Prio> Pair; |
64 |
/// |
|
60 |
/// Functor type for comparing the priorities. |
|
65 | 61 |
typedef CMP Compare; |
66 | 62 |
|
67 |
/// \brief Type to represent the |
|
63 |
/// \brief Type to represent the states of the items. |
|
68 | 64 |
/// |
69 |
/// Each Item element have a state associated to it. It may be "in heap", |
|
70 |
/// "pre heap" or "post heap". The latter two are indifferent from the |
|
65 |
/// Each item has a state associated to it. It can be "in heap", |
|
66 |
/// "pre-heap" or "post-heap". The latter two are indifferent from the |
|
71 | 67 |
/// heap's point of view, but may be useful to the user. |
72 | 68 |
/// |
73 | 69 |
/// The item-int map must be initialized in such way that it assigns |
74 | 70 |
/// \c PRE_HEAP (<tt>-1</tt>) to any element to be put in the heap. |
75 | 71 |
enum State { |
76 | 72 |
IN_HEAP = 0, ///< = 0. |
... | ... |
@@ -81,48 +77,49 @@ |
81 | 77 |
private: |
82 | 78 |
std::vector<Pair> _data; |
83 | 79 |
Compare _comp; |
84 | 80 |
ItemIntMap &_iim; |
85 | 81 |
|
86 | 82 |
public: |
87 |
|
|
83 |
|
|
84 |
/// \brief Constructor. |
|
88 | 85 |
/// |
89 |
/// The constructor. |
|
90 |
/// \param map should be given to the constructor, since it is used |
|
91 |
/// internally to handle the cross references. The value of the map |
|
92 |
/// must be \c PRE_HEAP (<tt>-1</tt>) for every item. |
|
86 |
/// Constructor. |
|
87 |
/// \param map A map that assigns \c int values to the items. |
|
88 |
/// It is used internally to handle the cross references. |
|
89 |
/// The assigned value must be \c PRE_HEAP (<tt>-1</tt>) for each item. |
|
93 | 90 |
explicit BinHeap(ItemIntMap &map) : _iim(map) {} |
94 | 91 |
|
95 |
/// \brief |
|
92 |
/// \brief Constructor. |
|
96 | 93 |
/// |
97 |
/// The constructor. |
|
98 |
/// \param map should be given to the constructor, since it is used |
|
99 |
/// internally to handle the cross references. The value of the map |
|
100 |
/// should be PRE_HEAP (-1) for each element. |
|
101 |
/// |
|
102 |
/// \param comp The comparator function object. |
|
94 |
/// Constructor. |
|
95 |
/// \param map A map that assigns \c int values to the items. |
|
96 |
/// It is used internally to handle the cross references. |
|
97 |
/// The assigned value must be \c PRE_HEAP (<tt>-1</tt>) for each item. |
|
98 |
/// \param comp The function object used for comparing the priorities. |
|
103 | 99 |
BinHeap(ItemIntMap &map, const Compare &comp) |
104 | 100 |
: _iim(map), _comp(comp) {} |
105 | 101 |
|
106 | 102 |
|
107 |
/// The number of items stored in the heap. |
|
103 |
/// \brief The number of items stored in the heap. |
|
108 | 104 |
/// |
109 |
/// |
|
105 |
/// This function returns the number of items stored in the heap. |
|
110 | 106 |
int size() const { return _data.size(); } |
111 | 107 |
|
112 |
/// \brief |
|
108 |
/// \brief Check if the heap is empty. |
|
113 | 109 |
/// |
114 |
/// |
|
110 |
/// This function returns \c true if the heap is empty. |
|
115 | 111 |
bool empty() const { return _data.empty(); } |
116 | 112 |
|
117 |
/// \brief Make |
|
113 |
/// \brief Make the heap empty. |
|
118 | 114 |
/// |
119 |
/// Make empty this heap. It does not change the cross reference map. |
|
120 |
/// If you want to reuse what is not surely empty you should first clear |
|
121 |
/// the heap and after that you should set the cross reference map for |
|
122 |
/// each item to \c PRE_HEAP. |
|
115 |
/// This functon makes the heap empty. |
|
116 |
/// It does not change the cross reference map. If you want to reuse |
|
117 |
/// a heap that is not surely empty, you should first clear it and |
|
118 |
/// then you should set the cross reference map to \c PRE_HEAP |
|
119 |
/// for each item. |
|
123 | 120 |
void clear() { |
124 | 121 |
_data.clear(); |
125 | 122 |
} |
126 | 123 |
|
127 | 124 |
private: |
128 | 125 |
static int parent(int i) { return (i-1)/2; } |
... | ... |
@@ -168,93 +165,97 @@ |
168 | 165 |
void move(const Pair &p, int i) { |
169 | 166 |
_data[i] = p; |
170 | 167 |
_iim.set(p.first, i); |
171 | 168 |
} |
172 | 169 |
|
173 | 170 |
public: |
171 |
|
|
174 | 172 |
/// \brief Insert a pair of item and priority into the heap. |
175 | 173 |
/// |
176 |
/// |
|
174 |
/// This function inserts \c p.first to the heap with priority |
|
175 |
/// \c p.second. |
|
177 | 176 |
/// \param p The pair to insert. |
177 |
/// \pre \c p.first must not be stored in the heap. |
|
178 | 178 |
void push(const Pair &p) { |
179 | 179 |
int n = _data.size(); |
180 | 180 |
_data.resize(n+1); |
181 | 181 |
bubble_up(n, p); |
182 | 182 |
} |
183 | 183 |
|
184 |
/// \brief Insert an item into the heap with the given |
|
184 |
/// \brief Insert an item into the heap with the given priority. |
|
185 | 185 |
/// |
186 |
/// |
|
186 |
/// This function inserts the given item into the heap with the |
|
187 |
/// given priority. |
|
187 | 188 |
/// \param i The item to insert. |
188 | 189 |
/// \param p The priority of the item. |
190 |
/// \pre \e i must not be stored in the heap. |
|
189 | 191 |
void push(const Item &i, const Prio &p) { push(Pair(i,p)); } |
190 | 192 |
|
191 |
/// \brief |
|
193 |
/// \brief Return the item having minimum priority. |
|
192 | 194 |
/// |
193 |
/// This method returns the item with minimum priority relative to \c |
|
194 |
/// Compare. |
|
195 |
/// |
|
195 |
/// This function returns the item having minimum priority. |
|
196 |
/// \pre The heap must be non-empty. |
|
196 | 197 |
Item top() const { |
197 | 198 |
return _data[0].first; |
198 | 199 |
} |
199 | 200 |
|
200 |
/// \brief |
|
201 |
/// \brief The minimum priority. |
|
201 | 202 |
/// |
202 |
/// It returns the minimum priority relative to \c Compare. |
|
203 |
/// \pre The heap must be nonempty. |
|
203 |
/// This function returns the minimum priority. |
|
204 |
/// \pre The heap must be non-empty. |
|
204 | 205 |
Prio prio() const { |
205 | 206 |
return _data[0].second; |
206 | 207 |
} |
207 | 208 |
|
208 |
/// \brief |
|
209 |
/// \brief Remove the item having minimum priority. |
|
209 | 210 |
/// |
210 |
/// This method deletes the item with minimum priority relative to \c |
|
211 |
/// Compare from the heap. |
|
211 |
/// This function removes the item having minimum priority. |
|
212 | 212 |
/// \pre The heap must be non-empty. |
213 | 213 |
void pop() { |
214 | 214 |
int n = _data.size()-1; |
215 | 215 |
_iim.set(_data[0].first, POST_HEAP); |
216 | 216 |
if (n > 0) { |
217 | 217 |
bubble_down(0, _data[n], n); |
218 | 218 |
} |
219 | 219 |
_data.pop_back(); |
220 | 220 |
} |
221 | 221 |
|
222 |
/// \brief |
|
222 |
/// \brief Remove the given item from the heap. |
|
223 | 223 |
/// |
224 |
/// This method deletes item \c i from the heap. |
|
225 |
/// \param i The item to erase. |
|
226 |
/// |
|
224 |
/// This function removes the given item from the heap if it is |
|
225 |
/// already stored. |
|
226 |
/// \param i The item to delete. |
|
227 |
/// \pre \e i must be in the heap. |
|
227 | 228 |
void erase(const Item &i) { |
228 | 229 |
int h = _iim[i]; |
229 | 230 |
int n = _data.size()-1; |
230 | 231 |
_iim.set(_data[h].first, POST_HEAP); |
231 | 232 |
if( h < n ) { |
232 | 233 |
if ( bubble_up(h, _data[n]) == h) { |
233 | 234 |
bubble_down(h, _data[n], n); |
234 | 235 |
} |
235 | 236 |
} |
236 | 237 |
_data.pop_back(); |
237 | 238 |
} |
238 | 239 |
|
239 |
|
|
240 |
/// \brief Returns the priority of \c i. |
|
240 |
/// \brief The priority of the given item. |
|
241 | 241 |
/// |
242 |
/// This function returns the priority of |
|
242 |
/// This function returns the priority of the given item. |
|
243 | 243 |
/// \param i The item. |
244 |
/// \pre \ |
|
244 |
/// \pre \e i must be in the heap. |
|
245 | 245 |
Prio operator[](const Item &i) const { |
246 | 246 |
int idx = _iim[i]; |
247 | 247 |
return _data[idx].second; |
248 | 248 |
} |
249 | 249 |
|
250 |
/// \brief \c i gets to the heap with priority \c p independently |
|
251 |
/// if \c i was already there. |
|
250 |
/// \brief Set the priority of an item or insert it, if it is |
|
251 |
/// not stored in the heap. |
|
252 | 252 |
/// |
253 |
/// This method calls \ref push(\c i, \c p) if \c i is not stored |
|
254 |
/// in the heap and sets the priority of \c i to \c p otherwise. |
|
253 |
/// This method sets the priority of the given item if it is |
|
254 |
/// already stored in the heap. Otherwise it inserts the given |
|
255 |
/// item into the heap with the given priority. |
|
255 | 256 |
/// \param i The item. |
256 | 257 |
/// \param p The priority. |
257 | 258 |
void set(const Item &i, const Prio &p) { |
258 | 259 |
int idx = _iim[i]; |
259 | 260 |
if( idx < 0 ) { |
260 | 261 |
push(i,p); |
... | ... |
@@ -264,56 +265,54 @@ |
264 | 265 |
} |
265 | 266 |
else { |
266 | 267 |
bubble_down(idx, Pair(i,p), _data.size()); |
267 | 268 |
} |
268 | 269 |
} |
269 | 270 |
|
270 |
/// \brief |
|
271 |
/// \brief Decrease the priority of an item to the given value. |
|
271 | 272 |
/// |
272 |
/// This |
|
273 |
/// This function decreases the priority of an item to the given value. |
|
273 | 274 |
/// \param i The item. |
274 | 275 |
/// \param p The priority. |
275 |
/// \pre \c i must be stored in the heap with priority at least \c |
|
276 |
/// p relative to \c Compare. |
|
276 |
/// \pre \e i must be stored in the heap with priority at least \e p. |
|
277 | 277 |
void decrease(const Item &i, const Prio &p) { |
278 | 278 |
int idx = _iim[i]; |
279 | 279 |
bubble_up(idx, Pair(i,p)); |
280 | 280 |
} |
281 | 281 |
|
282 |
/// \brief |
|
282 |
/// \brief Increase the priority of an item to the given value. |
|
283 | 283 |
/// |
284 |
/// This |
|
284 |
/// This function increases the priority of an item to the given value. |
|
285 | 285 |
/// \param i The item. |
286 | 286 |
/// \param p The priority. |
287 |
/// \pre \c i must be stored in the heap with priority at most \c |
|
288 |
/// p relative to \c Compare. |
|
287 |
/// \pre \e i must be stored in the heap with priority at most \e p. |
|
289 | 288 |
void increase(const Item &i, const Prio &p) { |
290 | 289 |
int idx = _iim[i]; |
291 | 290 |
bubble_down(idx, Pair(i,p), _data.size()); |
292 | 291 |
} |
293 | 292 |
|
294 |
/// \brief Returns if \c item is in, has already been in, or has |
|
295 |
/// never been in the heap. |
|
293 |
/// \brief Return the state of an item. |
|
296 | 294 |
/// |
297 |
/// This method returns PRE_HEAP if \c item has never been in the |
|
298 |
/// heap, IN_HEAP if it is in the heap at the moment, and POST_HEAP |
|
299 |
/// otherwise. In the latter case it is possible that \c item will |
|
300 |
/// get back to the heap again. |
|
295 |
/// This method returns \c PRE_HEAP if the given item has never |
|
296 |
/// been in the heap, \c IN_HEAP if it is in the heap at the moment, |
|
297 |
/// and \c POST_HEAP otherwise. |
|
298 |
/// In the latter case it is possible that the item will get back |
|
299 |
/// to the heap again. |
|
301 | 300 |
/// \param i The item. |
302 | 301 |
State state(const Item &i) const { |
303 | 302 |
int s = _iim[i]; |
304 | 303 |
if( s>=0 ) |
305 | 304 |
s=0; |
306 | 305 |
return State(s); |
307 | 306 |
} |
308 | 307 |
|
309 |
/// \brief |
|
308 |
/// \brief Set the state of an item in the heap. |
|
310 | 309 |
/// |
311 |
/// Sets the state of the \c item in the heap. It can be used to |
|
312 |
/// manually clear the heap when it is important to achive the |
|
313 |
/// |
|
310 |
/// This function sets the state of the given item in the heap. |
|
311 |
/// It can be used to manually clear the heap when it is important |
|
312 |
/// to achive better time complexity. |
|
314 | 313 |
/// \param i The item. |
315 | 314 |
/// \param st The state. It should not be \c IN_HEAP. |
316 | 315 |
void state(const Item& i, State st) { |
317 | 316 |
switch (st) { |
318 | 317 |
case POST_HEAP: |
319 | 318 |
case PRE_HEAP: |
... | ... |
@@ -324,18 +323,19 @@ |
324 | 323 |
break; |
325 | 324 |
case IN_HEAP: |
326 | 325 |
break; |
327 | 326 |
} |
328 | 327 |
} |
329 | 328 |
|
330 |
/// \brief |
|
329 |
/// \brief Replace an item in the heap. |
|
331 | 330 |
/// |
332 |
/// The \c i item is replaced with \c j item. The \c i item should |
|
333 |
/// be in the heap, while the \c j should be out of the heap. The |
|
334 |
/// \c i item will out of the heap and \c j will be in the heap |
|
335 |
/// with the same prioriority as prevoiusly the \c i item. |
|
331 |
/// This function replaces item \c i with item \c j. |
|
332 |
/// Item \c i must be in the heap, while \c j must be out of the heap. |
|
333 |
/// After calling this method, item \c i will be out of the |
|
334 |
/// heap and \c j will be in the heap with the same prioriority |
|
335 |
/// as item \c i had before. |
|
336 | 336 |
void replace(const Item& i, const Item& j) { |
337 | 337 |
int idx = _iim[i]; |
338 | 338 |
_iim.set(i, _iim[j]); |
339 | 339 |
_iim.set(j, idx); |
340 | 340 |
_data[idx].first = j; |
341 | 341 |
} |
... | ... |
@@ -18,13 +18,13 @@ |
18 | 18 |
|
19 | 19 |
#ifndef LEMON_BUCKET_HEAP_H |
20 | 20 |
#define LEMON_BUCKET_HEAP_H |
21 | 21 |
|
22 | 22 |
///\ingroup auxdat |
23 | 23 |
///\file |
24 |
///\brief Bucket |
|
24 |
///\brief Bucket heap implementation. |
|
25 | 25 |
|
26 | 26 |
#include <vector> |
27 | 27 |
#include <utility> |
28 | 28 |
#include <functional> |
29 | 29 |
|
30 | 30 |
namespace lemon { |
... | ... |
@@ -52,85 +52,93 @@ |
52 | 52 |
}; |
53 | 53 |
|
54 | 54 |
} |
55 | 55 |
|
56 | 56 |
/// \ingroup auxdat |
57 | 57 |
/// |
58 |
/// \brief |
|
58 |
/// \brief Bucket heap data structure. |
|
59 | 59 |
/// |
60 |
/// This class implements the \e bucket \e heap data structure. A \e heap |
|
61 |
/// is a data structure for storing items with specified values called \e |
|
62 |
/// priorities in such a way that finding the item with minimum priority is |
|
63 |
/// efficient. The bucket heap is very simple implementation, it can store |
|
64 |
/// only integer priorities and it stores for each priority in the |
|
65 |
/// \f$ [0..C) \f$ range a list of items. So it should be used only when |
|
66 |
/// the |
|
60 |
/// This class implements the \e bucket \e heap data structure. |
|
61 |
/// It practically conforms to the \ref concepts::Heap "heap concept", |
|
62 |
/// but it has some limitations. |
|
67 | 63 |
/// |
68 |
/// \param IM A read and write Item int map, used internally |
|
69 |
/// to handle the cross references. |
|
70 |
/// \param MIN If the given parameter is false then instead of the |
|
71 |
/// minimum value the maximum can be retrivied with the top() and |
|
72 |
/// |
|
64 |
/// The bucket heap is a very simple structure. It can store only |
|
65 |
/// \c int priorities and it maintains a list of items for each priority |
|
66 |
/// in the range <tt>[0..C)</tt>. So it should only be used when the |
|
67 |
/// priorities are small. It is not intended to use as a Dijkstra heap. |
|
68 |
/// |
|
69 |
/// \tparam IM A read-writable item map with \c int values, used |
|
70 |
/// internally to handle the cross references. |
|
71 |
/// \tparam MIN Indicate if the heap is a \e min-heap or a \e max-heap. |
|
72 |
/// The default is \e min-heap. If this parameter is set to \c false, |
|
73 |
/// then the comparison is reversed, so the top(), prio() and pop() |
|
74 |
/// functions deal with the item having maximum priority instead of the |
|
75 |
/// minimum. |
|
76 |
/// |
|
77 |
/// \sa SimpleBucketHeap |
|
73 | 78 |
template <typename IM, bool MIN = true> |
74 | 79 |
class BucketHeap { |
75 | 80 |
|
76 | 81 |
public: |
77 |
/// \e |
|
78 |
typedef typename IM::Key Item; |
|
79 |
|
|
82 |
|
|
83 |
/// Type of the item-int map. |
|
84 |
typedef IM ItemIntMap; |
|
85 |
/// Type of the priorities. |
|
80 | 86 |
typedef int Prio; |
81 |
/// \e |
|
82 |
typedef std::pair<Item, Prio> Pair; |
|
83 |
/// \e |
|
84 |
typedef IM ItemIntMap; |
|
87 |
/// Type of the items stored in the heap. |
|
88 |
typedef typename ItemIntMap::Key Item; |
|
89 |
/// Type of the item-priority pairs. |
|
90 |
typedef std::pair<Item,Prio> Pair; |
|
85 | 91 |
|
86 | 92 |
private: |
87 | 93 |
|
88 | 94 |
typedef _bucket_heap_bits::DirectionTraits<MIN> Direction; |
89 | 95 |
|
90 | 96 |
public: |
91 | 97 |
|
92 |
/// \brief Type to represent the |
|
98 |
/// \brief Type to represent the states of the items. |
|
93 | 99 |
/// |
94 |
/// Each Item element have a state associated to it. It may be "in heap", |
|
95 |
/// "pre heap" or "post heap". The latter two are indifferent from the |
|
100 |
/// Each item has a state associated to it. It can be "in heap", |
|
101 |
/// "pre-heap" or "post-heap". The latter two are indifferent from the |
|
96 | 102 |
/// heap's point of view, but may be useful to the user. |
97 | 103 |
/// |
98 | 104 |
/// The item-int map must be initialized in such way that it assigns |
99 | 105 |
/// \c PRE_HEAP (<tt>-1</tt>) to any element to be put in the heap. |
100 | 106 |
enum State { |
101 | 107 |
IN_HEAP = 0, ///< = 0. |
102 | 108 |
PRE_HEAP = -1, ///< = -1. |
103 | 109 |
POST_HEAP = -2 ///< = -2. |
104 | 110 |
}; |
105 | 111 |
|
106 | 112 |
public: |
107 |
|
|
113 |
|
|
114 |
/// \brief Constructor. |
|
108 | 115 |
/// |
109 |
/// The constructor. |
|
110 |
/// \param map should be given to the constructor, since it is used |
|
111 |
/// internally to handle the cross references. The value of the map |
|
112 |
/// should be PRE_HEAP (-1) for each element. |
|
116 |
/// Constructor. |
|
117 |
/// \param map A map that assigns \c int values to the items. |
|
118 |
/// It is used internally to handle the cross references. |
|
119 |
/// The assigned value must be \c PRE_HEAP (<tt>-1</tt>) for each item. |
|
113 | 120 |
explicit BucketHeap(ItemIntMap &map) : _iim(map), _minimum(0) {} |
114 | 121 |
|
115 |
/// The number of items stored in the heap. |
|
122 |
/// \brief The number of items stored in the heap. |
|
116 | 123 |
/// |
117 |
/// |
|
124 |
/// This function returns the number of items stored in the heap. |
|
118 | 125 |
int size() const { return _data.size(); } |
119 | 126 |
|
120 |
/// \brief |
|
127 |
/// \brief Check if the heap is empty. |
|
121 | 128 |
/// |
122 |
/// |
|
129 |
/// This function returns \c true if the heap is empty. |
|
123 | 130 |
bool empty() const { return _data.empty(); } |
124 | 131 |
|
125 |
/// \brief Make |
|
132 |
/// \brief Make the heap empty. |
|
126 | 133 |
/// |
127 |
/// Make empty this heap. It does not change the cross reference |
|
128 |
/// map. If you want to reuse a heap what is not surely empty you |
|
129 |
/// should first clear the heap and after that you should set the |
|
130 |
/// cross reference map for each item to \c PRE_HEAP. |
|
134 |
/// This functon makes the heap empty. |
|
135 |
/// It does not change the cross reference map. If you want to reuse |
|
136 |
/// a heap that is not surely empty, you should first clear it and |
|
137 |
/// then you should set the cross reference map to \c PRE_HEAP |
|
138 |
/// for each item. |
|
131 | 139 |
void clear() { |
132 | 140 |
_data.clear(); _first.clear(); _minimum = 0; |
133 | 141 |
} |
134 | 142 |
|
135 | 143 |
private: |
136 | 144 |
|
... | ... |
@@ -171,99 +179,105 @@ |
171 | 179 |
} |
172 | 180 |
_first[_data[idx].value] = idx; |
173 | 181 |
_data[idx].prev = -1; |
174 | 182 |
} |
175 | 183 |
|
176 | 184 |
public: |
185 |
|
|
177 | 186 |
/// \brief Insert a pair of item and priority into the heap. |
178 | 187 |
/// |
179 |
/// |
|
188 |
/// This function inserts \c p.first to the heap with priority |
|
189 |
/// \c p.second. |
|
180 | 190 |
/// \param p The pair to insert. |
191 |
/// \pre \c p.first must not be stored in the heap. |
|
181 | 192 |
void push(const Pair& p) { |
182 | 193 |
push(p.first, p.second); |
183 | 194 |
} |
184 | 195 |
|
185 | 196 |
/// \brief Insert an item into the heap with the given priority. |
186 | 197 |
/// |
187 |
/// |
|
198 |
/// This function inserts the given item into the heap with the |
|
199 |
/// given priority. |
|
188 | 200 |
/// \param i The item to insert. |
189 | 201 |
/// \param p The priority of the item. |
202 |
/// \pre \e i must not be stored in the heap. |
|
190 | 203 |
void push(const Item &i, const Prio &p) { |
191 | 204 |
int idx = _data.size(); |
192 | 205 |
_iim[i] = idx; |
193 | 206 |
_data.push_back(BucketItem(i, p)); |
194 | 207 |
lace(idx); |
195 | 208 |
if (Direction::less(p, _minimum)) { |
196 | 209 |
_minimum = p; |
197 | 210 |
} |
198 | 211 |
} |
199 | 212 |
|
200 |
/// \brief |
|
213 |
/// \brief Return the item having minimum priority. |
|
201 | 214 |
/// |
202 |
/// This method returns the item with minimum priority. |
|
203 |
/// \pre The heap must be nonempty. |
|
215 |
/// This function returns the item having minimum priority. |
|
216 |
/// \pre The heap must be non-empty. |
|
204 | 217 |
Item top() const { |
205 | 218 |
while (_first[_minimum] == -1) { |
206 | 219 |
Direction::increase(_minimum); |
207 | 220 |
} |
208 | 221 |
return _data[_first[_minimum]].item; |
209 | 222 |
} |
210 | 223 |
|
211 |
/// \brief |
|
224 |
/// \brief The minimum priority. |
|
212 | 225 |
/// |
213 |
/// It returns the minimum priority. |
|
214 |
/// \pre The heap must be nonempty. |
|
226 |
/// This function returns the minimum priority. |
|
227 |
/// \pre The heap must be non-empty. |
|
215 | 228 |
Prio prio() const { |
216 | 229 |
while (_first[_minimum] == -1) { |
217 | 230 |
Direction::increase(_minimum); |
218 | 231 |
} |
219 | 232 |
return _minimum; |
220 | 233 |
} |
221 | 234 |
|
222 |
/// \brief |
|
235 |
/// \brief Remove the item having minimum priority. |
|
223 | 236 |
/// |
224 |
/// This |
|
237 |
/// This function removes the item having minimum priority. |
|
225 | 238 |
/// \pre The heap must be non-empty. |
226 | 239 |
void pop() { |
227 | 240 |
while (_first[_minimum] == -1) { |
228 | 241 |
Direction::increase(_minimum); |
229 | 242 |
} |
230 | 243 |
int idx = _first[_minimum]; |
231 | 244 |
_iim[_data[idx].item] = -2; |
232 | 245 |
unlace(idx); |
233 | 246 |
relocate_last(idx); |
234 | 247 |
} |
235 | 248 |
|
236 |
/// \brief |
|
249 |
/// \brief Remove the given item from the heap. |
|
237 | 250 |
/// |
238 |
/// This method deletes item \c i from the heap, if \c i was |
|
239 |
/// already stored in the heap. |
|
240 |
/// |
|
251 |
/// This function removes the given item from the heap if it is |
|
252 |
/// already stored. |
|
253 |
/// \param i The item to delete. |
|
254 |
/// \pre \e i must be in the heap. |
|
241 | 255 |
void erase(const Item &i) { |
242 | 256 |
int idx = _iim[i]; |
243 | 257 |
_iim[_data[idx].item] = -2; |
244 | 258 |
unlace(idx); |
245 | 259 |
relocate_last(idx); |
246 | 260 |
} |
247 | 261 |
|
248 |
|
|
249 |
/// \brief Returns the priority of \c i. |
|
262 |
/// \brief The priority of the given item. |
|
250 | 263 |
/// |
251 |
/// This function returns the priority of item \c i. |
|
252 |
/// \pre \c i must be in the heap. |
|
264 |
/// This function returns the priority of the given item. |
|
253 | 265 |
/// \param i The item. |
266 |
/// \pre \e i must be in the heap. |
|
254 | 267 |
Prio operator[](const Item &i) const { |
255 | 268 |
int idx = _iim[i]; |
256 | 269 |
return _data[idx].value; |
257 | 270 |
} |
258 | 271 |
|
259 |
/// \brief \c i gets to the heap with priority \c p independently |
|
260 |
/// if \c i was already there. |
|
272 |
/// \brief Set the priority of an item or insert it, if it is |
|
273 |
/// not stored in the heap. |
|
261 | 274 |
/// |
262 |
/// This method calls \ref push(\c i, \c p) if \c i is not stored |
|
263 |
/// in the heap and sets the priority of \c i to \c p otherwise. |
|
275 |
/// This method sets the priority of the given item if it is |
|
276 |
/// already stored in the heap. Otherwise it inserts the given |
|
277 |
/// item into the heap with the given priority. |
|
264 | 278 |
/// \param i The item. |
265 | 279 |
/// \param p The priority. |
266 | 280 |
void set(const Item &i, const Prio &p) { |
267 | 281 |
int idx = _iim[i]; |
268 | 282 |
if (idx < 0) { |
269 | 283 |
push(i, p); |
... | ... |
@@ -271,62 +285,60 @@ |
271 | 285 |
decrease(i, p); |
272 | 286 |
} else { |
273 | 287 |
increase(i, p); |
274 | 288 |
} |
275 | 289 |
} |
276 | 290 |
|
277 |
/// \brief |
|
291 |
/// \brief Decrease the priority of an item to the given value. |
|
278 | 292 |
/// |
279 |
/// This method decreases the priority of item \c i to \c p. |
|
280 |
/// \pre \c i must be stored in the heap with priority at least \c |
|
281 |
/// |
|
293 |
/// This function decreases the priority of an item to the given value. |
|
282 | 294 |
/// \param i The item. |
283 | 295 |
/// \param p The priority. |
296 |
/// \pre \e i must be stored in the heap with priority at least \e p. |
|
284 | 297 |
void decrease(const Item &i, const Prio &p) { |
285 | 298 |
int idx = _iim[i]; |
286 | 299 |
unlace(idx); |
287 | 300 |
_data[idx].value = p; |
288 | 301 |
if (Direction::less(p, _minimum)) { |
289 | 302 |
_minimum = p; |
290 | 303 |
} |
291 | 304 |
lace(idx); |
292 | 305 |
} |
293 | 306 |
|
294 |
/// \brief |
|
307 |
/// \brief Increase the priority of an item to the given value. |
|
295 | 308 |
/// |
296 |
/// This method sets the priority of item \c i to \c p. |
|
297 |
/// \pre \c i must be stored in the heap with priority at most \c |
|
298 |
/// |
|
309 |
/// This function increases the priority of an item to the given value. |
|
299 | 310 |
/// \param i The item. |
300 | 311 |
/// \param p The priority. |
312 |
/// \pre \e i must be stored in the heap with priority at most \e p. |
|
301 | 313 |
void increase(const Item &i, const Prio &p) { |
302 | 314 |
int idx = _iim[i]; |
303 | 315 |
unlace(idx); |
304 | 316 |
_data[idx].value = p; |
305 | 317 |
lace(idx); |
306 | 318 |
} |
307 | 319 |
|
308 |
/// \brief Returns if \c item is in, has already been in, or has |
|
309 |
/// never been in the heap. |
|
320 |
/// \brief Return the state of an item. |
|
310 | 321 |
/// |
311 |
/// This method returns PRE_HEAP if \c item has never been in the |
|
312 |
/// heap, IN_HEAP if it is in the heap at the moment, and POST_HEAP |
|
313 |
/// otherwise. In the latter case it is possible that \c item will |
|
314 |
/// get back to the heap again. |
|
322 |
/// This method returns \c PRE_HEAP if the given item has never |
|
323 |
/// been in the heap, \c IN_HEAP if it is in the heap at the moment, |
|
324 |
/// and \c POST_HEAP otherwise. |
|
325 |
/// In the latter case it is possible that the item will get back |
|
326 |
/// to the heap again. |
|
315 | 327 |
/// \param i The item. |
316 | 328 |
State state(const Item &i) const { |
317 | 329 |
int idx = _iim[i]; |
318 | 330 |
if (idx >= 0) idx = 0; |
319 | 331 |
return State(idx); |
320 | 332 |
} |
321 | 333 |
|
322 |
/// \brief |
|
334 |
/// \brief Set the state of an item in the heap. |
|
323 | 335 |
/// |
324 |
/// Sets the state of the \c item in the heap. It can be used to |
|
325 |
/// manually clear the heap when it is important to achive the |
|
326 |
/// |
|
336 |
/// This function sets the state of the given item in the heap. |
|
337 |
/// It can be used to manually clear the heap when it is important |
|
338 |
/// to achive better time complexity. |
|
327 | 339 |
/// \param i The item. |
328 | 340 |
/// \param st The state. It should not be \c IN_HEAP. |
329 | 341 |
void state(const Item& i, State st) { |
330 | 342 |
switch (st) { |
331 | 343 |
case POST_HEAP: |
332 | 344 |
case PRE_HEAP: |
... | ... |
@@ -358,102 +370,118 @@ |
358 | 370 |
mutable int _minimum; |
359 | 371 |
|
360 | 372 |
}; // class BucketHeap |
361 | 373 |
|
362 | 374 |
/// \ingroup auxdat |
363 | 375 |
/// |
364 |
/// \brief |
|
376 |
/// \brief Simplified bucket heap data structure. |
|
365 | 377 |
/// |
366 | 378 |
/// This class implements a simplified \e bucket \e heap data |
367 |
/// structure. It does not provide some functionality but it faster |
|
368 |
/// and simplier data structure than the BucketHeap. The main |
|
369 |
/// difference is that the BucketHeap stores for every key a double |
|
370 |
/// linked list while this class stores just simple lists. In the |
|
371 |
/// other way it does not support erasing each elements just the |
|
372 |
/// minimal and it does not supports key increasing, decreasing. |
|
379 |
/// structure. It does not provide some functionality, but it is |
|
380 |
/// faster and simpler than BucketHeap. The main difference is |
|
381 |
/// that BucketHeap stores a doubly-linked list for each key while |
|
382 |
/// this class stores only simply-linked lists. It supports erasing |
|
383 |
/// only for the item having minimum priority and it does not support |
|
384 |
/// key increasing and decreasing. |
|
373 | 385 |
/// |
374 |
/// \param IM A read and write Item int map, used internally |
|
375 |
/// to handle the cross references. |
|
376 |
/// \param MIN If the given parameter is false then instead of the |
|
377 |
/// minimum value the maximum can be retrivied with the top() and |
|
378 |
/// |
|
386 |
/// Note that this implementation does not conform to the |
|
387 |
/// \ref concepts::Heap "heap concept" due to the lack of some |
|
388 |
/// functionality. |
|
389 |
/// |
|
390 |
/// \tparam IM A read-writable item map with \c int values, used |
|
391 |
/// internally to handle the cross references. |
|
392 |
/// \tparam MIN Indicate if the heap is a \e min-heap or a \e max-heap. |
|
393 |
/// The default is \e min-heap. If this parameter is set to \c false, |
|
394 |
/// then the comparison is reversed, so the top(), prio() and pop() |
|
395 |
/// functions deal with the item having maximum priority instead of the |
|
396 |
/// minimum. |
|
379 | 397 |
/// |
380 | 398 |
/// \sa BucketHeap |
381 | 399 |
template <typename IM, bool MIN = true > |
382 | 400 |
class SimpleBucketHeap { |
383 | 401 |
|
384 | 402 |
public: |
385 |
|
|
403 |
|
|
404 |
/// Type of the item-int map. |
|
405 |
typedef IM ItemIntMap; |
|
406 |
/// Type of the priorities. |
|
386 | 407 |
typedef int Prio; |
387 |
typedef std::pair<Item, Prio> Pair; |
|
388 |
typedef IM ItemIntMap; |
|
408 |
/// Type of the items stored in the heap. |
|
409 |
typedef typename ItemIntMap::Key Item; |
|
410 |
/// Type of the item-priority pairs. |
|
411 |
typedef std::pair<Item,Prio> Pair; |
|
389 | 412 |
|
390 | 413 |
private: |
391 | 414 |
|
392 | 415 |
typedef _bucket_heap_bits::DirectionTraits<MIN> Direction; |
393 | 416 |
|
394 | 417 |
public: |
395 | 418 |
|
396 |
/// \brief Type to represent the |
|
419 |
/// \brief Type to represent the states of the items. |
|
397 | 420 |
/// |
398 |
/// Each Item element have a state associated to it. It may be "in heap", |
|
399 |
/// "pre heap" or "post heap". The latter two are indifferent from the |
|
421 |
/// Each item has a state associated to it. It can be "in heap", |
|
422 |
/// "pre-heap" or "post-heap". The latter two are indifferent from the |
|
400 | 423 |
/// heap's point of view, but may be useful to the user. |
401 | 424 |
/// |
402 | 425 |
/// The item-int map must be initialized in such way that it assigns |
403 | 426 |
/// \c PRE_HEAP (<tt>-1</tt>) to any element to be put in the heap. |
404 | 427 |
enum State { |
405 | 428 |
IN_HEAP = 0, ///< = 0. |
406 | 429 |
PRE_HEAP = -1, ///< = -1. |
407 | 430 |
POST_HEAP = -2 ///< = -2. |
408 | 431 |
}; |
409 | 432 |
|
410 | 433 |
public: |
411 | 434 |
|
412 |
/// \brief |
|
435 |
/// \brief Constructor. |
|
413 | 436 |
/// |
414 |
/// The constructor. |
|
415 |
/// \param map should be given to the constructor, since it is used |
|
416 |
/// internally to handle the cross references. The value of the map |
|
417 |
/// should be PRE_HEAP (-1) for each element. |
|
437 |
/// Constructor. |
|
438 |
/// \param map A map that assigns \c int values to the items. |
|
439 |
/// It is used internally to handle the cross references. |
|
440 |
/// The assigned value must be \c PRE_HEAP (<tt>-1</tt>) for each item. |
|
418 | 441 |
explicit SimpleBucketHeap(ItemIntMap &map) |
419 | 442 |
: _iim(map), _free(-1), _num(0), _minimum(0) {} |
420 | 443 |
|
421 |
/// \brief |
|
444 |
/// \brief The number of items stored in the heap. |
|
422 | 445 |
/// |
423 |
/// |
|
446 |
/// This function returns the number of items stored in the heap. |
|
424 | 447 |
int size() const { return _num; } |
425 | 448 |
|
426 |
/// \brief |
|
449 |
/// \brief Check if the heap is empty. |
|
427 | 450 |
/// |
428 |
/// |
|
451 |
/// This function returns \c true if the heap is empty. |
|
429 | 452 |
bool empty() const { return _num == 0; } |
430 | 453 |
|
431 |
/// \brief Make |
|
454 |
/// \brief Make the heap empty. |
|
432 | 455 |
/// |
433 |
/// Make empty this heap. It does not change the cross reference |
|
434 |
/// map. If you want to reuse a heap what is not surely empty you |
|
435 |
/// should first clear the heap and after that you should set the |
|
436 |
/// cross reference map for each item to \c PRE_HEAP. |
|
456 |
/// This functon makes the heap empty. |
|
457 |
/// It does not change the cross reference map. If you want to reuse |
|
458 |
/// a heap that is not surely empty, you should first clear it and |
|
459 |
/// then you should set the cross reference map to \c PRE_HEAP |
|
460 |
/// for each item. |
|
437 | 461 |
void clear() { |
438 | 462 |
_data.clear(); _first.clear(); _free = -1; _num = 0; _minimum = 0; |
439 | 463 |
} |
440 | 464 |
|
441 | 465 |
/// \brief Insert a pair of item and priority into the heap. |
442 | 466 |
/// |
443 |
/// |
|
467 |
/// This function inserts \c p.first to the heap with priority |
|
468 |
/// \c p.second. |
|
444 | 469 |
/// \param p The pair to insert. |
470 |
/// \pre \c p.first must not be stored in the heap. |
|
445 | 471 |
void push(const Pair& p) { |
446 | 472 |
push(p.first, p.second); |
447 | 473 |
} |
448 | 474 |
|
449 | 475 |
/// \brief Insert an item into the heap with the given priority. |
450 | 476 |
/// |
451 |
/// |
|
477 |
/// This function inserts the given item into the heap with the |
|
478 |
/// given priority. |
|
452 | 479 |
/// \param i The item to insert. |
453 | 480 |
/// \param p The priority of the item. |
481 |
/// \pre \e i must not be stored in the heap. |
|
454 | 482 |
void push(const Item &i, const Prio &p) { |
455 | 483 |
int idx; |
456 | 484 |
if (_free == -1) { |
457 | 485 |
idx = _data.size(); |
458 | 486 |
_data.push_back(BucketItem(i)); |
459 | 487 |
} else { |
... | ... |
@@ -468,37 +496,37 @@ |
468 | 496 |
if (Direction::less(p, _minimum)) { |
469 | 497 |
_minimum = p; |
470 | 498 |
} |
471 | 499 |
++_num; |
472 | 500 |
} |
473 | 501 |
|
474 |
/// \brief |
|
502 |
/// \brief Return the item having minimum priority. |
|
475 | 503 |
/// |
476 |
/// This method returns the item with minimum priority. |
|
477 |
/// \pre The heap must be nonempty. |
|
504 |
/// This function returns the item having minimum priority. |
|
505 |
/// \pre The heap must be non-empty. |
|
478 | 506 |
Item top() const { |
479 | 507 |
while (_first[_minimum] == -1) { |
480 | 508 |
Direction::increase(_minimum); |
481 | 509 |
} |
482 | 510 |
return _data[_first[_minimum]].item; |
483 | 511 |
} |
484 | 512 |
|
485 |
/// \brief |
|
513 |
/// \brief The minimum priority. |
|
486 | 514 |
/// |
487 |
/// It returns the minimum priority. |
|
488 |
/// \pre The heap must be nonempty. |
|
515 |
/// This function returns the minimum priority. |
|
516 |
/// \pre The heap must be non-empty. |
|
489 | 517 |
Prio prio() const { |
490 | 518 |
while (_first[_minimum] == -1) { |
491 | 519 |
Direction::increase(_minimum); |
492 | 520 |
} |
493 | 521 |
return _minimum; |
494 | 522 |
} |
495 | 523 |
|
496 |
/// \brief |
|
524 |
/// \brief Remove the item having minimum priority. |
|
497 | 525 |
/// |
498 |
/// This |
|
526 |
/// This function removes the item having minimum priority. |
|
499 | 527 |
/// \pre The heap must be non-empty. |
500 | 528 |
void pop() { |
501 | 529 |
while (_first[_minimum] == -1) { |
502 | 530 |
Direction::increase(_minimum); |
503 | 531 |
} |
504 | 532 |
int idx = _first[_minimum]; |
... | ... |
@@ -506,40 +534,39 @@ |
506 | 534 |
_first[_minimum] = _data[idx].next; |
507 | 535 |
_data[idx].next = _free; |
508 | 536 |
_free = idx; |
509 | 537 |
--_num; |
510 | 538 |
} |
511 | 539 |
|
512 |
/// \brief |
|
540 |
/// \brief The priority of the given item. |
|
513 | 541 |
/// |
514 |
/// This function returns the priority of item \c i. |
|
515 |
/// \warning This operator is not a constant time function |
|
516 |
/// because it scans the whole data structure to find the proper |
|
517 |
/// value. |
|
518 |
/// |
|
542 |
/// This function returns the priority of the given item. |
|
519 | 543 |
/// \param i The item. |
544 |
/// \pre \e i must be in the heap. |
|
545 |
/// \warning This operator is not a constant time function because |
|
546 |
/// it scans the whole data structure to find the proper value. |
|
520 | 547 |
Prio operator[](const Item &i) const { |
521 |
for (int k = 0; k < _first.size(); ++k) { |
|
548 |
for (int k = 0; k < int(_first.size()); ++k) { |
|
522 | 549 |
int idx = _first[k]; |
523 | 550 |
while (idx != -1) { |
524 | 551 |
if (_data[idx].item == i) { |
525 | 552 |
return k; |
526 | 553 |
} |
527 | 554 |
idx = _data[idx].next; |
528 | 555 |
} |
529 | 556 |
} |
530 | 557 |
return -1; |
531 | 558 |
} |
532 | 559 |
|
533 |
/// \brief Returns if \c item is in, has already been in, or has |
|
534 |
/// never been in the heap. |
|
560 |
/// \brief Return the state of an item. |
|
535 | 561 |
/// |
536 |
/// This method returns PRE_HEAP if \c item has never been in the |
|
537 |
/// heap, IN_HEAP if it is in the heap at the moment, and POST_HEAP |
|
538 |
/// otherwise. In the latter case it is possible that \c item will |
|
539 |
/// get back to the heap again. |
|
562 |
/// This method returns \c PRE_HEAP if the given item has never |
|
563 |
/// been in the heap, \c IN_HEAP if it is in the heap at the moment, |
|
564 |
/// and \c POST_HEAP otherwise. |
|
565 |
/// In the latter case it is possible that the item will get back |
|
566 |
/// to the heap again. |
|
540 | 567 |
/// \param i The item. |
541 | 568 |
State state(const Item &i) const { |
542 | 569 |
int idx = _iim[i]; |
543 | 570 |
if (idx >= 0) idx = 0; |
544 | 571 |
return State(idx); |
545 | 572 |
} |
... | ... |
@@ -13,46 +13,52 @@ |
13 | 13 |
* This software is provided "AS IS" with no warranty of any kind, |
14 | 14 |
* express or implied, and with no claim as to its suitability for any |
15 | 15 |
* purpose. |
16 | 16 |
* |
17 | 17 |
*/ |
18 | 18 |
|
19 |
#ifndef LEMON_CONCEPTS_HEAP_H |
|
20 |
#define LEMON_CONCEPTS_HEAP_H |
|
21 |
|
|
19 | 22 |
///\ingroup concept |
20 | 23 |
///\file |
21 | 24 |
///\brief The concept of heaps. |
22 | 25 |
|
23 |
#ifndef LEMON_CONCEPTS_HEAP_H |
|
24 |
#define LEMON_CONCEPTS_HEAP_H |
|
25 |
|
|
26 | 26 |
#include <lemon/core.h> |
27 | 27 |
#include <lemon/concept_check.h> |
28 | 28 |
|
29 | 29 |
namespace lemon { |
30 | 30 |
|
31 | 31 |
namespace concepts { |
32 | 32 |
|
33 | 33 |
/// \addtogroup concept |
34 | 34 |
/// @{ |
35 | 35 |
|
36 | 36 |
/// \brief The heap concept. |
37 | 37 |
/// |
38 |
/// Concept class describing the main interface of heaps. A \e heap |
|
39 |
/// is a data structure for storing items with specified values called |
|
40 |
/// \e priorities in such a way that finding the item with minimum |
|
41 |
/// priority is efficient. In a heap one can change the priority of an |
|
42 |
/// |
|
38 |
/// This concept class describes the main interface of heaps. |
|
39 |
/// The various heap structures are efficient |
|
40 |
/// implementations of the abstract data type \e priority \e queue. |
|
41 |
/// They store items with specified values called \e priorities |
|
42 |
/// in such a way that finding and removing the item with minimum |
|
43 |
/// priority are efficient. The basic operations are adding and |
|
44 |
/// erasing items, changing the priority of an item, etc. |
|
43 | 45 |
/// |
44 |
/// \tparam PR Type of the priority of the items. |
|
45 |
/// \tparam IM A read and writable item map with int values, used |
|
46 |
/// Heaps are crucial in several algorithms, such as Dijkstra and Prim. |
|
47 |
/// Any class that conforms to this concept can be used easily in such |
|
48 |
/// algorithms. |
|
49 |
/// |
|
50 |
/// \tparam PR Type of the priorities of the items. |
|
51 |
/// \tparam IM A read-writable item map with \c int values, used |
|
46 | 52 |
/// internally to handle the cross references. |
47 |
/// \tparam |
|
53 |
/// \tparam CMP A functor class for comparing the priorities. |
|
48 | 54 |
/// The default is \c std::less<PR>. |
49 | 55 |
#ifdef DOXYGEN |
50 |
template <typename PR, typename IM, typename |
|
56 |
template <typename PR, typename IM, typename CMP> |
|
51 | 57 |
#else |
52 |
template <typename PR, typename IM> |
|
58 |
template <typename PR, typename IM, typename CMP = std::less<PR> > |
|
53 | 59 |
#endif |
54 | 60 |
class Heap { |
55 | 61 |
public: |
56 | 62 |
|
57 | 63 |
/// Type of the item-int map. |
58 | 64 |
typedef IM ItemIntMap; |
... | ... |
@@ -61,129 +67,145 @@ |
61 | 67 |
/// Type of the items stored in the heap. |
62 | 68 |
typedef typename ItemIntMap::Key Item; |
63 | 69 |
|
64 | 70 |
/// \brief Type to represent the states of the items. |
65 | 71 |
/// |
66 | 72 |
/// Each item has a state associated to it. It can be "in heap", |
67 |
/// "pre heap" or "post heap". The later two are indifferent |
|
68 |
/// from the point of view of the heap, but may be useful for |
|
69 |
/// |
|
73 |
/// "pre-heap" or "post-heap". The latter two are indifferent from the |
|
74 |
/// heap's point of view, but may be useful to the user. |
|
70 | 75 |
/// |
71 | 76 |
/// The item-int map must be initialized in such way that it assigns |
72 | 77 |
/// \c PRE_HEAP (<tt>-1</tt>) to any element to be put in the heap. |
73 | 78 |
enum State { |
74 | 79 |
IN_HEAP = 0, ///< = 0. The "in heap" state constant. |
75 |
PRE_HEAP = -1, ///< = -1. The "pre heap" state constant. |
|
76 |
POST_HEAP = -2 ///< = -2. The "post heap" state constant. |
|
80 |
PRE_HEAP = -1, ///< = -1. The "pre-heap" state constant. |
|
81 |
POST_HEAP = -2 ///< = -2. The "post-heap" state constant. |
|
77 | 82 |
}; |
78 | 83 |
|
79 |
/// \brief |
|
84 |
/// \brief Constructor. |
|
80 | 85 |
/// |
81 |
/// |
|
86 |
/// Constructor. |
|
82 | 87 |
/// \param map A map that assigns \c int values to keys of type |
83 | 88 |
/// \c Item. It is used internally by the heap implementations to |
84 | 89 |
/// handle the cross references. The assigned value must be |
85 |
/// \c PRE_HEAP (<tt>-1</tt>) for |
|
90 |
/// \c PRE_HEAP (<tt>-1</tt>) for each item. |
|
86 | 91 |
explicit Heap(ItemIntMap &map) {} |
87 | 92 |
|
93 |
/// \brief Constructor. |
|
94 |
/// |
|
95 |
/// Constructor. |
|
96 |
/// \param map A map that assigns \c int values to keys of type |
|
97 |
/// \c Item. It is used internally by the heap implementations to |
|
98 |
/// handle the cross references. The assigned value must be |
|
99 |
/// \c PRE_HEAP (<tt>-1</tt>) for each item. |
|
100 |
/// \param comp The function object used for comparing the priorities. |
|
101 |
explicit Heap(ItemIntMap &map, const CMP &comp) {} |
|
102 |
|
|
88 | 103 |
/// \brief The number of items stored in the heap. |
89 | 104 |
/// |
90 |
/// |
|
105 |
/// This function returns the number of items stored in the heap. |
|
91 | 106 |
int size() const { return 0; } |
92 | 107 |
|
93 |
/// \brief |
|
108 |
/// \brief Check if the heap is empty. |
|
94 | 109 |
/// |
95 |
/// |
|
110 |
/// This function returns \c true if the heap is empty. |
|
96 | 111 |
bool empty() const { return false; } |
97 | 112 |
|
98 |
/// \brief |
|
113 |
/// \brief Make the heap empty. |
|
99 | 114 |
/// |
100 |
/// Makes the heap empty. |
|
101 |
void clear(); |
|
115 |
/// This functon makes the heap empty. |
|
116 |
/// It does not change the cross reference map. If you want to reuse |
|
117 |
/// a heap that is not surely empty, you should first clear it and |
|
118 |
/// then you should set the cross reference map to \c PRE_HEAP |
|
119 |
/// for each item. |
|
120 |
void clear() {} |
|
102 | 121 |
|
103 |
/// \brief |
|
122 |
/// \brief Insert an item into the heap with the given priority. |
|
104 | 123 |
/// |
105 |
/// |
|
124 |
/// This function inserts the given item into the heap with the |
|
125 |
/// given priority. |
|
106 | 126 |
/// \param i The item to insert. |
107 | 127 |
/// \param p The priority of the item. |
128 |
/// \pre \e i must not be stored in the heap. |
|
108 | 129 |
void push(const Item &i, const Prio &p) {} |
109 | 130 |
|
110 |
/// \brief |
|
131 |
/// \brief Return the item having minimum priority. |
|
111 | 132 |
/// |
112 |
/// |
|
133 |
/// This function returns the item having minimum priority. |
|
113 | 134 |
/// \pre The heap must be non-empty. |
114 | 135 |
Item top() const {} |
115 | 136 |
|
116 | 137 |
/// \brief The minimum priority. |
117 | 138 |
/// |
118 |
/// |
|
139 |
/// This function returns the minimum priority. |
|
119 | 140 |
/// \pre The heap must be non-empty. |
120 | 141 |
Prio prio() const {} |
121 | 142 |
|
122 |
/// \brief |
|
143 |
/// \brief Remove the item having minimum priority. |
|
123 | 144 |
/// |
124 |
/// |
|
145 |
/// This function removes the item having minimum priority. |
|
125 | 146 |
/// \pre The heap must be non-empty. |
126 | 147 |
void pop() {} |
127 | 148 |
|
128 |
/// \brief |
|
149 |
/// \brief Remove the given item from the heap. |
|
129 | 150 |
/// |
130 |
/// |
|
151 |
/// This function removes the given item from the heap if it is |
|
152 |
/// already stored. |
|
131 | 153 |
/// \param i The item to delete. |
154 |
/// \pre \e i must be in the heap. |
|
132 | 155 |
void erase(const Item &i) {} |
133 | 156 |
|
134 |
/// \brief The priority of |
|
157 |
/// \brief The priority of the given item. |
|
135 | 158 |
/// |
136 |
/// |
|
159 |
/// This function returns the priority of the given item. |
|
137 | 160 |
/// \param i The item. |
138 |
/// \pre \ |
|
161 |
/// \pre \e i must be in the heap. |
|
139 | 162 |
Prio operator[](const Item &i) const {} |
140 | 163 |
|
141 |
/// \brief |
|
164 |
/// \brief Set the priority of an item or insert it, if it is |
|
142 | 165 |
/// not stored in the heap. |
143 | 166 |
/// |
144 | 167 |
/// This method sets the priority of the given item if it is |
145 |
/// already stored in the heap. |
|
146 |
/// Otherwise it inserts the given item with the given priority. |
|
168 |
/// already stored in the heap. Otherwise it inserts the given |
|
169 |
/// item into the heap with the given priority. |
|
147 | 170 |
/// |
148 | 171 |
/// \param i The item. |
149 | 172 |
/// \param p The priority. |
150 | 173 |
void set(const Item &i, const Prio &p) {} |
151 | 174 |
|
152 |
/// \brief |
|
175 |
/// \brief Decrease the priority of an item to the given value. |
|
153 | 176 |
/// |
154 |
/// |
|
177 |
/// This function decreases the priority of an item to the given value. |
|
155 | 178 |
/// \param i The item. |
156 | 179 |
/// \param p The priority. |
157 |
/// \pre \ |
|
180 |
/// \pre \e i must be stored in the heap with priority at least \e p. |
|
158 | 181 |
void decrease(const Item &i, const Prio &p) {} |
159 | 182 |
|
160 |
/// \brief |
|
183 |
/// \brief Increase the priority of an item to the given value. |
|
161 | 184 |
/// |
162 |
/// |
|
185 |
/// This function increases the priority of an item to the given value. |
|
163 | 186 |
/// \param i The item. |
164 | 187 |
/// \param p The priority. |
165 |
/// \pre \ |
|
188 |
/// \pre \e i must be stored in the heap with priority at most \e p. |
|
166 | 189 |
void increase(const Item &i, const Prio &p) {} |
167 | 190 |
|
168 |
/// \brief Returns if an item is in, has already been in, or has |
|
169 |
/// never been in the heap. |
|
191 |
/// \brief Return the state of an item. |
|
170 | 192 |
/// |
171 | 193 |
/// This method returns \c PRE_HEAP if the given item has never |
172 | 194 |
/// been in the heap, \c IN_HEAP if it is in the heap at the moment, |
173 | 195 |
/// and \c POST_HEAP otherwise. |
174 | 196 |
/// In the latter case it is possible that the item will get back |
175 | 197 |
/// to the heap again. |
176 | 198 |
/// \param i The item. |
177 | 199 |
State state(const Item &i) const {} |
178 | 200 |
|
179 |
/// \brief |
|
201 |
/// \brief Set the state of an item in the heap. |
|
180 | 202 |
/// |
181 |
/// Sets the state of the given item in the heap. It can be used |
|
182 |
/// to manually clear the heap when it is important to achive the |
|
183 |
/// |
|
203 |
/// This function sets the state of the given item in the heap. |
|
204 |
/// It can be used to manually clear the heap when it is important |
|
205 |
/// to achive better time complexity. |
|
184 | 206 |
/// \param i The item. |
185 | 207 |
/// \param st The state. It should not be \c IN_HEAP. |
186 | 208 |
void state(const Item& i, State st) {} |
187 | 209 |
|
188 | 210 |
|
189 | 211 |
template <typename _Heap> |
... | ... |
@@ -18,58 +18,54 @@ |
18 | 18 |
|
19 | 19 |
#ifndef LEMON_FIB_HEAP_H |
20 | 20 |
#define LEMON_FIB_HEAP_H |
21 | 21 |
|
22 | 22 |
///\file |
23 | 23 |
///\ingroup auxdat |
24 |
///\brief Fibonacci |
|
24 |
///\brief Fibonacci heap implementation. |
|
25 | 25 |
|
26 | 26 |
#include <vector> |
27 |
#include <utility> |
|
27 | 28 |
#include <functional> |
28 | 29 |
#include <lemon/math.h> |
29 | 30 |
|
30 | 31 |
namespace lemon { |
31 | 32 |
|
32 | 33 |
/// \ingroup auxdat |
33 | 34 |
/// |
34 |
///\brief Fibonacci |
|
35 |
/// \brief Fibonacci heap data structure. |
|
35 | 36 |
/// |
36 |
///This class implements the \e Fibonacci \e heap data structure. A \e heap |
|
37 |
///is a data structure for storing items with specified values called \e |
|
38 |
///priorities in such a way that finding the item with minimum priority is |
|
39 |
///efficient. \c CMP specifies the ordering of the priorities. In a heap |
|
40 |
/// |
|
37 |
/// This class implements the \e Fibonacci \e heap data structure. |
|
38 |
/// It fully conforms to the \ref concepts::Heap "heap concept". |
|
41 | 39 |
/// |
42 |
///The methods \ref increase and \ref erase are not efficient in a Fibonacci |
|
43 |
///heap. In case of many calls to these operations, it is better to use a |
|
44 |
///\ref |
|
40 |
/// The methods \ref increase() and \ref erase() are not efficient in a |
|
41 |
/// Fibonacci heap. In case of many calls of these operations, it is |
|
42 |
/// better to use other heap structure, e.g. \ref BinHeap "binary heap". |
|
45 | 43 |
/// |
46 |
///\param PRIO Type of the priority of the items. |
|
47 |
///\param IM A read and writable Item int map, used internally |
|
48 |
///to handle the cross references. |
|
49 |
///\param CMP A class for the ordering of the priorities. The |
|
50 |
///default is \c std::less<PRIO>. |
|
51 |
/// |
|
52 |
///\sa BinHeap |
|
53 |
///\sa Dijkstra |
|
44 |
/// \tparam PR Type of the priorities of the items. |
|
45 |
/// \tparam IM A read-writable item map with \c int values, used |
|
46 |
/// internally to handle the cross references. |
|
47 |
/// \tparam CMP A functor class for comparing the priorities. |
|
48 |
/// The default is \c std::less<PR>. |
|
54 | 49 |
#ifdef DOXYGEN |
55 |
template <typename |
|
50 |
template <typename PR, typename IM, typename CMP> |
|
56 | 51 |
#else |
57 |
template <typename |
|
52 |
template <typename PR, typename IM, typename CMP = std::less<PR> > |
|
58 | 53 |
#endif |
59 | 54 |
class FibHeap { |
60 | 55 |
public: |
61 |
|
|
56 |
|
|
57 |
/// Type of the item-int map. |
|
62 | 58 |
typedef IM ItemIntMap; |
63 |
///\e |
|
64 |
typedef PRIO Prio; |
|
65 |
/// |
|
59 |
/// Type of the priorities. |
|
60 |
typedef PR Prio; |
|
61 |
/// Type of the items stored in the heap. |
|
66 | 62 |
typedef typename ItemIntMap::Key Item; |
67 |
/// |
|
63 |
/// Type of the item-priority pairs. |
|
68 | 64 |
typedef std::pair<Item,Prio> Pair; |
69 |
/// |
|
65 |
/// Functor type for comparing the priorities. |
|
70 | 66 |
typedef CMP Compare; |
71 | 67 |
|
72 | 68 |
private: |
73 | 69 |
class Store; |
74 | 70 |
|
75 | 71 |
std::vector<Store> _data; |
... | ... |
@@ -77,80 +73,74 @@ |
77 | 73 |
ItemIntMap &_iim; |
78 | 74 |
Compare _comp; |
79 | 75 |
int _num; |
80 | 76 |
|
81 | 77 |
public: |
82 | 78 |
|
83 |
/// \brief Type to represent the |
|
79 |
/// \brief Type to represent the states of the items. |
|
84 | 80 |
/// |
85 |
/// Each Item element have a state associated to it. It may be "in heap", |
|
86 |
/// "pre heap" or "post heap". The latter two are indifferent from the |
|
81 |
/// Each item has a state associated to it. It can be "in heap", |
|
82 |
/// "pre-heap" or "post-heap". The latter two are indifferent from the |
|
87 | 83 |
/// heap's point of view, but may be useful to the user. |
88 | 84 |
/// |
89 | 85 |
/// The item-int map must be initialized in such way that it assigns |
90 | 86 |
/// \c PRE_HEAP (<tt>-1</tt>) to any element to be put in the heap. |
91 | 87 |
enum State { |
92 | 88 |
IN_HEAP = 0, ///< = 0. |
93 | 89 |
PRE_HEAP = -1, ///< = -1. |
94 | 90 |
POST_HEAP = -2 ///< = -2. |
95 | 91 |
}; |
96 | 92 |
|
97 |
/// \brief |
|
93 |
/// \brief Constructor. |
|
98 | 94 |
/// |
99 |
/// \c map should be given to the constructor, since it is |
|
100 |
/// used internally to handle the cross references. |
|
95 |
/// Constructor. |
|
96 |
/// \param map A map that assigns \c int values to the items. |
|
97 |
/// It is used internally to handle the cross references. |
|
98 |
/// The assigned value must be \c PRE_HEAP (<tt>-1</tt>) for each item. |
|
101 | 99 |
explicit FibHeap(ItemIntMap &map) |
102 | 100 |
: _minimum(0), _iim(map), _num() {} |
103 | 101 |
|
104 |
/// \brief |
|
102 |
/// \brief Constructor. |
|
105 | 103 |
/// |
106 |
/// \c map should be given to the constructor, since it is used |
|
107 |
/// internally to handle the cross references. \c comp is an |
|
108 |
/// |
|
104 |
/// Constructor. |
|
105 |
/// \param map A map that assigns \c int values to the items. |
|
106 |
/// It is used internally to handle the cross references. |
|
107 |
/// The assigned value must be \c PRE_HEAP (<tt>-1</tt>) for each item. |
|
108 |
/// \param comp The function object used for comparing the priorities. |
|
109 | 109 |
FibHeap(ItemIntMap &map, const Compare &comp) |
110 | 110 |
: _minimum(0), _iim(map), _comp(comp), _num() {} |
111 | 111 |
|
112 | 112 |
/// \brief The number of items stored in the heap. |
113 | 113 |
/// |
114 |
/// |
|
114 |
/// This function returns the number of items stored in the heap. |
|
115 | 115 |
int size() const { return _num; } |
116 | 116 |
|
117 |
/// \brief |
|
117 |
/// \brief Check if the heap is empty. |
|
118 | 118 |
/// |
119 |
/// |
|
119 |
/// This function returns \c true if the heap is empty. |
|
120 | 120 |
bool empty() const { return _num==0; } |
121 | 121 |
|
122 |
/// \brief Make |
|
122 |
/// \brief Make the heap empty. |
|
123 | 123 |
/// |
124 |
/// Make empty this heap. It does not change the cross reference |
|
125 |
/// map. If you want to reuse a heap what is not surely empty you |
|
126 |
/// should first clear the heap and after that you should set the |
|
127 |
/// cross reference map for each item to \c PRE_HEAP. |
|
124 |
/// This functon makes the heap empty. |
|
125 |
/// It does not change the cross reference map. If you want to reuse |
|
126 |
/// a heap that is not surely empty, you should first clear it and |
|
127 |
/// then you should set the cross reference map to \c PRE_HEAP |
|
128 |
/// for each item. |
|
128 | 129 |
void clear() { |
129 | 130 |
_data.clear(); _minimum = 0; _num = 0; |
130 | 131 |
} |
131 | 132 |
|
132 |
/// \brief \c item gets to the heap with priority \c value independently |
|
133 |
/// if \c item was already there. |
|
133 |
/// \brief Insert an item into the heap with the given priority. |
|
134 | 134 |
/// |
135 |
/// This method calls \ref push(\c item, \c value) if \c item is not |
|
136 |
/// stored in the heap and it calls \ref decrease(\c item, \c value) or |
|
137 |
/// \ref increase(\c item, \c value) otherwise. |
|
138 |
void set (const Item& item, const Prio& value) { |
|
139 |
int i=_iim[item]; |
|
140 |
if ( i >= 0 && _data[i].in ) { |
|
141 |
if ( _comp(value, _data[i].prio) ) decrease(item, value); |
|
142 |
if ( _comp(_data[i].prio, value) ) increase(item, value); |
|
143 |
} else push(item, value); |
|
144 |
} |
|
145 |
|
|
146 |
/// \brief Adds \c item to the heap with priority \c value. |
|
147 |
/// |
|
148 |
/// Adds \c item to the heap with priority \c value. |
|
149 |
/// \pre \c item must not be stored in the heap. |
|
150 |
void push (const Item& item, const Prio& value) { |
|
135 |
/// This function inserts the given item into the heap with the |
|
136 |
/// given priority. |
|
137 |
/// \param item The item to insert. |
|
138 |
/// \param prio The priority of the item. |
|
139 |
/// \pre \e item must not be stored in the heap. |
|
140 |
void push (const Item& item, const Prio& prio) { |
|
151 | 141 |
int i=_iim[item]; |
152 | 142 |
if ( i < 0 ) { |
153 | 143 |
int s=_data.size(); |
154 | 144 |
_iim.set( item, s ); |
155 | 145 |
Store st; |
156 | 146 |
st.name=item; |
... | ... |
@@ -165,46 +155,36 @@ |
165 | 155 |
|
166 | 156 |
if ( _num ) { |
167 | 157 |
_data[_data[_minimum].right_neighbor].left_neighbor=i; |
168 | 158 |
_data[i].right_neighbor=_data[_minimum].right_neighbor; |
169 | 159 |
_data[_minimum].right_neighbor=i; |
170 | 160 |
_data[i].left_neighbor=_minimum; |
171 |
if ( _comp( |
|
161 |
if ( _comp( prio, _data[_minimum].prio) ) _minimum=i; |
|
172 | 162 |
} else { |
173 | 163 |
_data[i].right_neighbor=_data[i].left_neighbor=i; |
174 | 164 |
_minimum=i; |
175 | 165 |
} |
176 |
_data[i].prio= |
|
166 |
_data[i].prio=prio; |
|
177 | 167 |
++_num; |
178 | 168 |
} |
179 | 169 |
|
180 |
/// \brief |
|
170 |
/// \brief Return the item having minimum priority. |
|
181 | 171 |
/// |
182 |
/// This method returns the item with minimum priority relative to \c |
|
183 |
/// Compare. |
|
184 |
/// |
|
172 |
/// This function returns the item having minimum priority. |
|
173 |
/// \pre The heap must be non-empty. |
|
185 | 174 |
Item top() const { return _data[_minimum].name; } |
186 | 175 |
|
187 |
/// \brief |
|
176 |
/// \brief The minimum priority. |
|
188 | 177 |
/// |
189 |
/// It returns the minimum priority relative to \c Compare. |
|
190 |
/// \pre The heap must be nonempty. |
|
191 |
|
|
178 |
/// This function returns the minimum priority. |
|
179 |
/// \pre The heap must be non-empty. |
|
180 |
Prio prio() const { return _data[_minimum].prio; } |
|
192 | 181 |
|
193 |
/// \brief |
|
182 |
/// \brief Remove the item having minimum priority. |
|
194 | 183 |
/// |
195 |
/// It returns the priority of \c item. |
|
196 |
/// \pre \c item must be in the heap. |
|
197 |
const Prio& operator[](const Item& item) const { |
|
198 |
return _data[_iim[item]].prio; |
|
199 |
} |
|
200 |
|
|
201 |
/// \brief Deletes the item with minimum priority relative to \c Compare. |
|
202 |
/// |
|
203 |
/// This method deletes the item with minimum priority relative to \c |
|
204 |
/// Compare from the heap. |
|
184 |
/// This function removes the item having minimum priority. |
|
205 | 185 |
/// \pre The heap must be non-empty. |
206 | 186 |
void pop() { |
207 | 187 |
/*The first case is that there are only one root.*/ |
208 | 188 |
if ( _data[_minimum].left_neighbor==_minimum ) { |
209 | 189 |
_data[_minimum].in=false; |
210 | 190 |
if ( _data[_minimum].degree!=0 ) { |
... | ... |
@@ -231,16 +211,18 @@ |
231 | 211 |
_minimum=right; |
232 | 212 |
balance(); |
233 | 213 |
} // the case where there are more roots |
234 | 214 |
--_num; |
235 | 215 |
} |
236 | 216 |
|
237 |
/// \brief |
|
217 |
/// \brief Remove the given item from the heap. |
|
238 | 218 |
/// |
239 |
/// This method deletes \c item from the heap, if \c item was already |
|
240 |
/// stored in the heap. It is quite inefficient in Fibonacci heaps. |
|
219 |
/// This function removes the given item from the heap if it is |
|
220 |
/// already stored. |
|
221 |
/// \param item The item to delete. |
|
222 |
/// \pre \e item must be in the heap. |
|
241 | 223 |
void erase (const Item& item) { |
242 | 224 |
int i=_iim[item]; |
243 | 225 |
|
244 | 226 |
if ( i >= 0 && _data[i].in ) { |
245 | 227 |
if ( _data[i].parent!=-1 ) { |
246 | 228 |
int p=_data[i].parent; |
... | ... |
@@ -249,63 +231,88 @@ |
249 | 231 |
} |
250 | 232 |
_minimum=i; //As if its prio would be -infinity |
251 | 233 |
pop(); |
252 | 234 |
} |
253 | 235 |
} |
254 | 236 |
|
255 |
/// \brief |
|
237 |
/// \brief The priority of the given item. |
|
256 | 238 |
/// |
257 |
/// This method decreases the priority of \c item to \c value. |
|
258 |
/// \pre \c item must be stored in the heap with priority at least \c |
|
259 |
/// value relative to \c Compare. |
|
260 |
void decrease (Item item, const Prio& value) { |
|
239 |
/// This function returns the priority of the given item. |
|
240 |
/// \param item The item. |
|
241 |
/// \pre \e item must be in the heap. |
|
242 |
Prio operator[](const Item& item) const { |
|
243 |
return _data[_iim[item]].prio; |
|
244 |
} |
|
245 |
|
|
246 |
/// \brief Set the priority of an item or insert it, if it is |
|
247 |
/// not stored in the heap. |
|
248 |
/// |
|
249 |
/// This method sets the priority of the given item if it is |
|
250 |
/// already stored in the heap. Otherwise it inserts the given |
|
251 |
/// item into the heap with the given priority. |
|
252 |
/// \param item The item. |
|
253 |
/// \param prio The priority. |
|
254 |
void set (const Item& item, const Prio& prio) { |
|
261 | 255 |
int i=_iim[item]; |
262 |
_data[i]. |
|
256 |
if ( i >= 0 && _data[i].in ) { |
|
257 |
if ( _comp(prio, _data[i].prio) ) decrease(item, prio); |
|
258 |
if ( _comp(_data[i].prio, prio) ) increase(item, prio); |
|
259 |
} else push(item, prio); |
|
260 |
} |
|
261 |
|
|
262 |
/// \brief Decrease the priority of an item to the given value. |
|
263 |
/// |
|
264 |
/// This function decreases the priority of an item to the given value. |
|
265 |
/// \param item The item. |
|
266 |
/// \param prio The priority. |
|
267 |
/// \pre \e item must be stored in the heap with priority at least \e prio. |
|
268 |
void decrease (const Item& item, const Prio& prio) { |
|
269 |
int i=_iim[item]; |
|
270 |
_data[i].prio=prio; |
|
263 | 271 |
int p=_data[i].parent; |
264 | 272 |
|
265 |
if ( p!=-1 && _comp( |
|
273 |
if ( p!=-1 && _comp(prio, _data[p].prio) ) { |
|
266 | 274 |
cut(i,p); |
267 | 275 |
cascade(p); |
268 | 276 |
} |
269 |
if ( _comp( |
|
277 |
if ( _comp(prio, _data[_minimum].prio) ) _minimum=i; |
|
270 | 278 |
} |
271 | 279 |
|
272 |
/// \brief |
|
280 |
/// \brief Increase the priority of an item to the given value. |
|
273 | 281 |
/// |
274 |
/// This method sets the priority of \c item to \c value. Though |
|
275 |
/// there is no precondition on the priority of \c item, this |
|
276 |
/// method should be used only if it is indeed necessary to increase |
|
277 |
/// (relative to \c Compare) the priority of \c item, because this |
|
278 |
/// method is inefficient. |
|
279 |
void increase (Item item, const Prio& value) { |
|
282 |
/// This function increases the priority of an item to the given value. |
|
283 |
/// \param item The item. |
|
284 |
/// \param prio The priority. |
|
285 |
/// \pre \e item must be stored in the heap with priority at most \e prio. |
|
286 |
void increase (const Item& item, const Prio& prio) { |
|
280 | 287 |
erase(item); |
281 |
push(item, |
|
288 |
push(item, prio); |
|
282 | 289 |
} |
283 | 290 |
|
284 |
|
|
285 |
/// \brief Returns if \c item is in, has already been in, or has never |
|
286 |
/// |
|
291 |
/// \brief Return the state of an item. |
|
287 | 292 |
/// |
288 |
/// This method returns PRE_HEAP if \c item has never been in the |
|
289 |
/// heap, IN_HEAP if it is in the heap at the moment, and POST_HEAP |
|
290 |
/// otherwise. In the latter case it is possible that \c item will |
|
291 |
/// get back to the heap again. |
|
293 |
/// This method returns \c PRE_HEAP if the given item has never |
|
294 |
/// been in the heap, \c IN_HEAP if it is in the heap at the moment, |
|
295 |
/// and \c POST_HEAP otherwise. |
|
296 |
/// In the latter case it is possible that the item will get back |
|
297 |
/// to the heap again. |
|
298 |
/// \param item The item. |
|
292 | 299 |
State state(const Item &item) const { |
293 | 300 |
int i=_iim[item]; |
294 | 301 |
if( i>=0 ) { |
295 | 302 |
if ( _data[i].in ) i=0; |
296 | 303 |
else i=-2; |
297 | 304 |
} |
298 | 305 |
return State(i); |
299 | 306 |
} |
300 | 307 |
|
301 |
/// \brief |
|
308 |
/// \brief Set the state of an item in the heap. |
|
302 | 309 |
/// |
303 |
/// Sets the state of the \c item in the heap. It can be used to |
|
304 |
/// manually clear the heap when it is important to achive the |
|
305 |
/// |
|
310 |
/// This function sets the state of the given item in the heap. |
|
311 |
/// It can be used to manually clear the heap when it is important |
|
312 |
/// to achive better time complexity. |
|
306 | 313 |
/// \param i The item. |
307 | 314 |
/// \param st The state. It should not be \c IN_HEAP. |
308 | 315 |
void state(const Item& i, State st) { |
309 | 316 |
switch (st) { |
310 | 317 |
case POST_HEAP: |
311 | 318 |
case PRE_HEAP: |
... | ... |
@@ -18,70 +18,68 @@ |
18 | 18 |
|
19 | 19 |
#ifndef LEMON_RADIX_HEAP_H |
20 | 20 |
#define LEMON_RADIX_HEAP_H |
21 | 21 |
|
22 | 22 |
///\ingroup auxdat |
23 | 23 |
///\file |
24 |
///\brief Radix |
|
24 |
///\brief Radix heap implementation. |
|
25 | 25 |
|
26 | 26 |
#include <vector> |
27 | 27 |
#include <lemon/error.h> |
28 | 28 |
|
29 | 29 |
namespace lemon { |
30 | 30 |
|
31 | 31 |
|
32 |
/// \ingroup |
|
32 |
/// \ingroup auxdat |
|
33 | 33 |
/// |
34 |
/// \brief |
|
34 |
/// \brief Radix heap data structure. |
|
35 | 35 |
/// |
36 |
/// This class implements the \e radix \e heap data structure. A \e heap |
|
37 |
/// is a data structure for storing items with specified values called \e |
|
38 |
/// priorities in such a way that finding the item with minimum priority is |
|
39 |
/// efficient. This heap type can store only items with \e int priority. |
|
40 |
/// In a heap one can change the priority of an item, add or erase an |
|
41 |
/// item, but the priority cannot be decreased under the last removed |
|
42 |
/// |
|
36 |
/// This class implements the \e radix \e heap data structure. |
|
37 |
/// It practically conforms to the \ref concepts::Heap "heap concept", |
|
38 |
/// but it has some limitations due its special implementation. |
|
39 |
/// The type of the priorities must be \c int and the priority of an |
|
40 |
/// item cannot be decreased under the priority of the last removed item. |
|
43 | 41 |
/// |
44 |
/// \param IM A read and writable Item int map, used internally |
|
45 |
/// to handle the cross references. |
|
46 |
/// |
|
47 |
/// \see BinHeap |
|
48 |
/// \ |
|
42 |
/// \tparam IM A read-writable item map with \c int values, used |
|
43 |
/// internally to handle the cross references. |
|
49 | 44 |
template <typename IM> |
50 | 45 |
class RadixHeap { |
51 | 46 |
|
52 | 47 |
public: |
53 |
|
|
48 |
|
|
49 |
/// Type of the item-int map. |
|
50 |
typedef IM ItemIntMap; |
|
51 |
/// Type of the priorities. |
|
54 | 52 |
typedef int Prio; |
55 |
|
|
53 |
/// Type of the items stored in the heap. |
|
54 |
typedef typename ItemIntMap::Key Item; |
|
56 | 55 |
|
57 | 56 |
/// \brief Exception thrown by RadixHeap. |
58 | 57 |
/// |
59 |
/// This Exception is thrown when a smaller priority |
|
60 |
/// is inserted into the \e RadixHeap then the last time erased. |
|
58 |
/// This exception is thrown when an item is inserted into a |
|
59 |
/// RadixHeap with a priority smaller than the last erased one. |
|
61 | 60 |
/// \see RadixHeap |
62 |
|
|
63 | 61 |
class UnderFlowPriorityError : public Exception { |
64 | 62 |
public: |
65 | 63 |
virtual const char* what() const throw() { |
66 | 64 |
return "lemon::RadixHeap::UnderFlowPriorityError"; |
67 | 65 |
} |
68 | 66 |
}; |
69 | 67 |
|
70 |
/// \brief Type to represent the |
|
68 |
/// \brief Type to represent the states of the items. |
|
71 | 69 |
/// |
72 |
/// Each Item element have a state associated to it. It may be "in heap", |
|
73 |
/// "pre heap" or "post heap". The latter two are indifferent from the |
|
70 |
/// Each item has a state associated to it. It can be "in heap", |
|
71 |
/// "pre-heap" or "post-heap". The latter two are indifferent from the |
|
74 | 72 |
/// heap's point of view, but may be useful to the user. |
75 | 73 |
/// |
76 |
/// The ItemIntMap \e should be initialized in such way that it maps |
|
77 |
/// PRE_HEAP (-1) to any element to be put in the heap... |
|
74 |
/// The item-int map must be initialized in such way that it assigns |
|
75 |
/// \c PRE_HEAP (<tt>-1</tt>) to any element to be put in the heap. |
|
78 | 76 |
enum State { |
79 |
IN_HEAP = 0, |
|
80 |
PRE_HEAP = -1, |
|
81 |
|
|
77 |
IN_HEAP = 0, ///< = 0. |
|
78 |
PRE_HEAP = -1, ///< = -1. |
|
79 |
POST_HEAP = -2 ///< = -2. |
|
82 | 80 |
}; |
83 | 81 |
|
84 | 82 |
private: |
85 | 83 |
|
86 | 84 |
struct RadixItem { |
87 | 85 |
int prev, next, box; |
... | ... |
@@ -98,53 +96,56 @@ |
98 | 96 |
|
99 | 97 |
std::vector<RadixItem> data; |
100 | 98 |
std::vector<RadixBox> boxes; |
101 | 99 |
|
102 | 100 |
ItemIntMap &_iim; |
103 | 101 |
|
102 |
public: |
|
104 | 103 |
|
105 |
public: |
|
106 |
/// \brief The constructor. |
|
104 |
/// \brief Constructor. |
|
107 | 105 |
/// |
108 |
/// The constructor. |
|
109 |
/// |
|
110 |
/// \param map It should be given to the constructor, since it is used |
|
111 |
/// internally to handle the cross references. The value of the map |
|
112 |
/// should be PRE_HEAP (-1) for each element. |
|
113 |
/// |
|
114 |
/// \param minimal The initial minimal value of the heap. |
|
115 |
/// \param capacity It determines the initial capacity of the heap. |
|
116 |
RadixHeap(ItemIntMap &map, int minimal = 0, int capacity = 0) |
|
117 |
: _iim(map) { |
|
118 |
boxes.push_back(RadixBox(minimal, 1)); |
|
119 |
boxes.push_back(RadixBox(minimal + 1, 1)); |
|
120 |
|
|
106 |
/// Constructor. |
|
107 |
/// \param map A map that assigns \c int values to the items. |
|
108 |
/// It is used internally to handle the cross references. |
|
109 |
/// The assigned value must be \c PRE_HEAP (<tt>-1</tt>) for each item. |
|
110 |
/// \param minimum The initial minimum value of the heap. |
|
111 |
/// \param capacity The initial capacity of the heap. |
|
112 |
RadixHeap(ItemIntMap &map, int minimum = 0, int capacity = 0) |
|
113 |
: _iim(map) |
|
114 |
{ |
|
115 |
boxes.push_back(RadixBox(minimum, 1)); |
|
116 |
boxes.push_back(RadixBox(minimum + 1, 1)); |
|
117 |
while (lower(boxes.size() - 1, capacity + minimum - 1)) { |
|
121 | 118 |
extend(); |
122 | 119 |
} |
123 | 120 |
} |
124 | 121 |
|
125 |
/// The number of items stored in the heap. |
|
122 |
/// \brief The number of items stored in the heap. |
|
126 | 123 |
/// |
127 |
/// |
|
124 |
/// This function returns the number of items stored in the heap. |
|
128 | 125 |
int size() const { return data.size(); } |
129 |
|
|
126 |
|
|
127 |
/// \brief Check if the heap is empty. |
|
130 | 128 |
/// |
131 |
/// |
|
129 |
/// This function returns \c true if the heap is empty. |
|
132 | 130 |
bool empty() const { return data.empty(); } |
133 | 131 |
|
134 |
/// \brief Make |
|
132 |
/// \brief Make the heap empty. |
|
135 | 133 |
/// |
136 |
/// Make empty this heap. It does not change the cross reference |
|
137 |
/// map. If you want to reuse a heap what is not surely empty you |
|
138 |
/// should first clear the heap and after that you should set the |
|
139 |
/// cross reference map for each item to \c PRE_HEAP. |
|
140 |
|
|
134 |
/// This functon makes the heap empty. |
|
135 |
/// It does not change the cross reference map. If you want to reuse |
|
136 |
/// a heap that is not surely empty, you should first clear it and |
|
137 |
/// then you should set the cross reference map to \c PRE_HEAP |
|
138 |
/// for each item. |
|
139 |
/// \param minimum The minimum value of the heap. |
|
140 |
/// \param capacity The capacity of the heap. |
|
141 |
void clear(int minimum = 0, int capacity = 0) { |
|
141 | 142 |
data.clear(); boxes.clear(); |
142 |
boxes.push_back(RadixBox(minimal, 1)); |
|
143 |
boxes.push_back(RadixBox(minimal + 1, 1)); |
|
144 |
|
|
143 |
boxes.push_back(RadixBox(minimum, 1)); |
|
144 |
boxes.push_back(RadixBox(minimum + 1, 1)); |
|
145 |
while (lower(boxes.size() - 1, capacity + minimum - 1)) { |
|
145 | 146 |
extend(); |
146 | 147 |
} |
147 | 148 |
} |
148 | 149 |
|
149 | 150 |
private: |
150 | 151 |
|
... | ... |
@@ -153,25 +154,25 @@ |
153 | 154 |
} |
154 | 155 |
|
155 | 156 |
bool lower(int box, Prio pr) { |
156 | 157 |
return pr >= boxes[box].min + boxes[box].size; |
157 | 158 |
} |
158 | 159 |
|
159 |
// |
|
160 |
// Remove item from the box list |
|
160 | 161 |
void remove(int index) { |
161 | 162 |
if (data[index].prev >= 0) { |
162 | 163 |
data[data[index].prev].next = data[index].next; |
163 | 164 |
} else { |
164 | 165 |
boxes[data[index].box].first = data[index].next; |
165 | 166 |
} |
166 | 167 |
if (data[index].next >= 0) { |
167 | 168 |
data[data[index].next].prev = data[index].prev; |
168 | 169 |
} |
169 | 170 |
} |
170 | 171 |
|
171 |
// |
|
172 |
// Insert item into the box list |
|
172 | 173 |
void insert(int box, int index) { |
173 | 174 |
if (boxes[box].first == -1) { |
174 | 175 |
boxes[box].first = index; |
175 | 176 |
data[index].next = data[index].prev = -1; |
176 | 177 |
} else { |
177 | 178 |
data[index].next = boxes[box].first; |
... | ... |
@@ -179,71 +180,70 @@ |
179 | 180 |
data[index].prev = -1; |
180 | 181 |
boxes[box].first = index; |
181 | 182 |
} |
182 | 183 |
data[index].box = box; |
183 | 184 |
} |
184 | 185 |
|
185 |
// |
|
186 |
// Add a new box to the box list |
|
186 | 187 |
void extend() { |
187 | 188 |
int min = boxes.back().min + boxes.back().size; |
188 | 189 |
int bs = 2 * boxes.back().size; |
189 | 190 |
boxes.push_back(RadixBox(min, bs)); |
190 | 191 |
} |
191 | 192 |
|
192 |
// |
|
193 |
// Move an item up into the proper box. |
|
193 | 194 |
void bubble_up(int index) { |
194 | 195 |
if (!lower(data[index].box, data[index].prio)) return; |
195 | 196 |
remove(index); |
196 | 197 |
int box = findUp(data[index].box, data[index].prio); |
197 | 198 |
insert(box, index); |
198 | 199 |
} |
199 | 200 |
|
200 |
// |
|
201 |
// Find up the proper box for the item with the given priority |
|
201 | 202 |
int findUp(int start, int pr) { |
202 | 203 |
while (lower(start, pr)) { |
203 | 204 |
if (++start == int(boxes.size())) { |
204 | 205 |
extend(); |
205 | 206 |
} |
206 | 207 |
} |
207 | 208 |
return start; |
208 | 209 |
} |
209 | 210 |
|
210 |
// |
|
211 |
// Move an item down into the proper box |
|
211 | 212 |
void bubble_down(int index) { |
212 | 213 |
if (!upper(data[index].box, data[index].prio)) return; |
213 | 214 |
remove(index); |
214 | 215 |
int box = findDown(data[index].box, data[index].prio); |
215 | 216 |
insert(box, index); |
216 | 217 |
} |
217 | 218 |
|
218 |
// |
|
219 |
// Find down the proper box for the item with the given priority |
|
219 | 220 |
int findDown(int start, int pr) { |
220 | 221 |
while (upper(start, pr)) { |
221 | 222 |
if (--start < 0) throw UnderFlowPriorityError(); |
222 | 223 |
} |
223 | 224 |
return start; |
224 | 225 |
} |
225 | 226 |
|
226 |
// |
|
227 |
// Find the first non-empty box |
|
227 | 228 |
int findFirst() { |
228 | 229 |
int first = 0; |
229 | 230 |
while (boxes[first].first == -1) ++first; |
230 | 231 |
return first; |
231 | 232 |
} |
232 | 233 |
|
233 |
// |
|
234 |
// Gives back the minimum priority of the given box |
|
234 | 235 |
int minValue(int box) { |
235 | 236 |
int min = data[boxes[box].first].prio; |
236 | 237 |
for (int k = boxes[box].first; k != -1; k = data[k].next) { |
237 | 238 |
if (data[k].prio < min) min = data[k].prio; |
238 | 239 |
} |
239 | 240 |
return min; |
240 | 241 |
} |
241 | 242 |
|
242 |
/// \brief Rearrange the items of the heap and makes the |
|
243 |
/// first box not empty. |
|
243 |
// Rearrange the items of the heap and make the first box non-empty |
|
244 | 244 |
void moveDown() { |
245 | 245 |
int box = findFirst(); |
246 | 246 |
if (box == 0) return; |
247 | 247 |
int min = minValue(box); |
248 | 248 |
for (int i = 0; i <= box; ++i) { |
249 | 249 |
boxes[i].min = min; |
... | ... |
@@ -274,86 +274,92 @@ |
274 | 274 |
} |
275 | 275 |
|
276 | 276 |
public: |
277 | 277 |
|
278 | 278 |
/// \brief Insert an item into the heap with the given priority. |
279 | 279 |
/// |
280 |
/// |
|
280 |
/// This function inserts the given item into the heap with the |
|
281 |
/// given priority. |
|
281 | 282 |
/// \param i The item to insert. |
282 | 283 |
/// \param p The priority of the item. |
284 |
/// \pre \e i must not be stored in the heap. |
|
285 |
/// \warning This method may throw an \c UnderFlowPriorityException. |
|
283 | 286 |
void push(const Item &i, const Prio &p) { |
284 | 287 |
int n = data.size(); |
285 | 288 |
_iim.set(i, n); |
286 | 289 |
data.push_back(RadixItem(i, p)); |
287 | 290 |
while (lower(boxes.size() - 1, p)) { |
288 | 291 |
extend(); |
289 | 292 |
} |
290 | 293 |
int box = findDown(boxes.size() - 1, p); |
291 | 294 |
insert(box, n); |
292 | 295 |
} |
293 | 296 |
|
294 |
/// \brief |
|
297 |
/// \brief Return the item having minimum priority. |
|
295 | 298 |
/// |
296 |
/// This method returns the item with minimum priority. |
|
297 |
/// \pre The heap must be nonempty. |
|
299 |
/// This function returns the item having minimum priority. |
|
300 |
/// \pre The heap must be non-empty. |
|
298 | 301 |
Item top() const { |
299 | 302 |
const_cast<RadixHeap<ItemIntMap>&>(*this).moveDown(); |
300 | 303 |
return data[boxes[0].first].item; |
301 | 304 |
} |
302 | 305 |
|
303 |
/// \brief |
|
306 |
/// \brief The minimum priority. |
|
304 | 307 |
/// |
305 |
/// It returns the minimum priority. |
|
306 |
/// \pre The heap must be nonempty. |
|
308 |
/// This function returns the minimum priority. |
|
309 |
/// \pre The heap must be non-empty. |
|
307 | 310 |
Prio prio() const { |
308 | 311 |
const_cast<RadixHeap<ItemIntMap>&>(*this).moveDown(); |
309 | 312 |
return data[boxes[0].first].prio; |
310 | 313 |
} |
311 | 314 |
|
312 |
/// \brief |
|
315 |
/// \brief Remove the item having minimum priority. |
|
313 | 316 |
/// |
314 |
/// This |
|
317 |
/// This function removes the item having minimum priority. |
|
315 | 318 |
/// \pre The heap must be non-empty. |
316 | 319 |
void pop() { |
317 | 320 |
moveDown(); |
318 | 321 |
int index = boxes[0].first; |
319 | 322 |
_iim[data[index].item] = POST_HEAP; |
320 | 323 |
remove(index); |
321 | 324 |
relocate_last(index); |
322 | 325 |
} |
323 | 326 |
|
324 |
/// \brief |
|
327 |
/// \brief Remove the given item from the heap. |
|
325 | 328 |
/// |
326 |
/// This method deletes item \c i from the heap, if \c i was |
|
327 |
/// already stored in the heap. |
|
328 |
/// |
|
329 |
/// This function removes the given item from the heap if it is |
|
330 |
/// already stored. |
|
331 |
/// \param i The item to delete. |
|
332 |
/// \pre \e i must be in the heap. |
|
329 | 333 |
void erase(const Item &i) { |
330 | 334 |
int index = _iim[i]; |
331 | 335 |
_iim[i] = POST_HEAP; |
332 | 336 |
remove(index); |
333 | 337 |
relocate_last(index); |
334 | 338 |
} |
335 | 339 |
|
336 |
/// \brief |
|
340 |
/// \brief The priority of the given item. |
|
337 | 341 |
/// |
338 |
/// This function returns the priority of item \c i. |
|
339 |
/// \pre \c i must be in the heap. |
|
342 |
/// This function returns the priority of the given item. |
|
340 | 343 |
/// \param i The item. |
344 |
/// \pre \e i must be in the heap. |
|
341 | 345 |
Prio operator[](const Item &i) const { |
342 | 346 |
int idx = _iim[i]; |
343 | 347 |
return data[idx].prio; |
344 | 348 |
} |
345 | 349 |
|
346 |
/// \brief \c i gets to the heap with priority \c p independently |
|
347 |
/// if \c i was already there. |
|
350 |
/// \brief Set the priority of an item or insert it, if it is |
|
351 |
/// not stored in the heap. |
|
348 | 352 |
/// |
349 |
/// This method calls \ref push(\c i, \c p) if \c i is not stored |
|
350 |
/// in the heap and sets the priority of \c i to \c p otherwise. |
|
351 |
/// |
|
353 |
/// This method sets the priority of the given item if it is |
|
354 |
/// already stored in the heap. Otherwise it inserts the given |
|
355 |
/// item into the heap with the given priority. |
|
352 | 356 |
/// \param i The item. |
353 | 357 |
/// \param p The priority. |
358 |
/// \pre \e i must be in the heap. |
|
359 |
/// \warning This method may throw an \c UnderFlowPriorityException. |
|
354 | 360 |
void set(const Item &i, const Prio &p) { |
355 | 361 |
int idx = _iim[i]; |
356 | 362 |
if( idx < 0 ) { |
357 | 363 |
push(i, p); |
358 | 364 |
} |
359 | 365 |
else if( p >= data[idx].prio ) { |
... | ... |
@@ -362,57 +368,56 @@ |
362 | 368 |
} else { |
363 | 369 |
data[idx].prio = p; |
364 | 370 |
bubble_down(idx); |
365 | 371 |
} |
366 | 372 |
} |
367 | 373 |
|
368 |
|
|
369 |
/// \brief Decreases the priority of \c i to \c p. |
|
374 |
/// \brief Decrease the priority of an item to the given value. |
|
370 | 375 |
/// |
371 |
/// This method decreases the priority of item \c i to \c p. |
|
372 |
/// \pre \c i must be stored in the heap with priority at least \c p, and |
|
373 |
/// |
|
376 |
/// This function decreases the priority of an item to the given value. |
|
374 | 377 |
/// \param i The item. |
375 | 378 |
/// \param p The priority. |
379 |
/// \pre \e i must be stored in the heap with priority at least \e p. |
|
380 |
/// \warning This method may throw an \c UnderFlowPriorityException. |
|
376 | 381 |
void decrease(const Item &i, const Prio &p) { |
377 | 382 |
int idx = _iim[i]; |
378 | 383 |
data[idx].prio = p; |
379 | 384 |
bubble_down(idx); |
380 | 385 |
} |
381 | 386 |
|
382 |
/// \brief |
|
387 |
/// \brief Increase the priority of an item to the given value. |
|
383 | 388 |
/// |
384 |
/// This method sets the priority of item \c i to \c p. |
|
385 |
/// \pre \c i must be stored in the heap with priority at most \c p |
|
389 |
/// This function increases the priority of an item to the given value. |
|
386 | 390 |
/// \param i The item. |
387 | 391 |
/// \param p The priority. |
392 |
/// \pre \e i must be stored in the heap with priority at most \e p. |
|
388 | 393 |
void increase(const Item &i, const Prio &p) { |
389 | 394 |
int idx = _iim[i]; |
390 | 395 |
data[idx].prio = p; |
391 | 396 |
bubble_up(idx); |
392 | 397 |
} |
393 | 398 |
|
394 |
/// \brief Returns if \c item is in, has already been in, or has |
|
395 |
/// never been in the heap. |
|
399 |
/// \brief Return the state of an item. |
|
396 | 400 |
/// |
397 |
/// This method returns PRE_HEAP if \c item has never been in the |
|
398 |
/// heap, IN_HEAP if it is in the heap at the moment, and POST_HEAP |
|
399 |
/// otherwise. In the latter case it is possible that \c item will |
|
400 |
/// get back to the heap again. |
|
401 |
/// This method returns \c PRE_HEAP if the given item has never |
|
402 |
/// been in the heap, \c IN_HEAP if it is in the heap at the moment, |
|
403 |
/// and \c POST_HEAP otherwise. |
|
404 |
/// In the latter case it is possible that the item will get back |
|
405 |
/// to the heap again. |
|
401 | 406 |
/// \param i The item. |
402 | 407 |
State state(const Item &i) const { |
403 | 408 |
int s = _iim[i]; |
404 | 409 |
if( s >= 0 ) s = 0; |
405 | 410 |
return State(s); |
406 | 411 |
} |
407 | 412 |
|
408 |
/// \brief |
|
413 |
/// \brief Set the state of an item in the heap. |
|
409 | 414 |
/// |
410 |
/// Sets the state of the \c item in the heap. It can be used to |
|
411 |
/// manually clear the heap when it is important to achive the |
|
412 |
/// |
|
415 |
/// This function sets the state of the given item in the heap. |
|
416 |
/// It can be used to manually clear the heap when it is important |
|
417 |
/// to achive better time complexity. |
|
413 | 418 |
/// \param i The item. |
414 | 419 |
/// \param st The state. It should not be \c IN_HEAP. |
415 | 420 |
void state(const Item& i, State st) { |
416 | 421 |
switch (st) { |
417 | 422 |
case POST_HEAP: |
418 | 423 |
case PRE_HEAP: |
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