Changes in lemon/bin_heap.h [683:9f529abcaebf:711:28cfac049a6a] in lemon1.2
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lemon/bin_heap.h
r683 r711 20 20 #define LEMON_BIN_HEAP_H 21 21 22 ///\ingroup auxdat22 ///\ingroup heaps 23 23 ///\file 24 ///\brief Binary Heap implementation.24 ///\brief Binary heap implementation. 25 25 26 26 #include <vector> … … 30 30 namespace lemon { 31 31 32 /// \ingroup auxdat32 /// \ingroup heaps 33 33 /// 34 /// \brief A Binary Heap implementation.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 readwritable 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 { 54 55 50 public: 56 ///\e 51 52 /// Type of the itemint map. 57 53 typedef IM ItemIntMap; 58 /// \e54 /// Type of the priorities. 59 55 typedef PR Prio; 60 /// \e56 /// Type of the items stored in the heap. 61 57 typedef typename ItemIntMap::Key Item; 62 /// \e58 /// Type of the itempriority pairs. 63 59 typedef std::pair<Item,Prio> Pair; 64 /// \e60 /// Functor type for comparing the priorities. 65 61 typedef CMP Compare; 66 62 67 /// \brief Type to represent the items states.68 /// 69 /// Each Item element have a state associated to it. It maybe "in heap",70 /// "pre heap" or "postheap". The latter two are indifferent from the63 /// \brief Type to represent the states of the items. 64 /// 65 /// Each item has a state associated to it. It can be "in heap", 66 /// "preheap" or "postheap". The latter two are indifferent from the 71 67 /// heap's point of view, but may be useful to the user. 72 68 /// … … 85 81 86 82 public: 87 /// \brief The constructor. 88 /// 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. 83 84 /// \brief Constructor. 85 /// 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 The constructor. 96 /// 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. 92 /// \brief Constructor. 93 /// 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.108 /// 109 /// \brief Returns the number of items stored in the heap.103 /// \brief The number of items stored in the heap. 104 /// 105 /// This function returns the number of items stored in the heap. 110 106 int size() const { return _data.size(); } 111 107 112 /// \brief Check s if the heap stores no items.113 /// 114 /// Returns \c true if and only if the heap stores no items.108 /// \brief Check if the heap is empty. 109 /// 110 /// This function returns \c true if the heap is empty. 115 111 bool empty() const { return _data.empty(); } 116 112 117 /// \brief Make empty this heap. 118 /// 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. 113 /// \brief Make the heap empty. 114 /// 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(); … … 128 125 static int parent(int i) { return (i1)/2; } 129 126 130 static int second _child(int i) { return 2*i+2; }127 static int secondChild(int i) { return 2*i+2; } 131 128 bool less(const Pair &p1, const Pair &p2) const { 132 129 return _comp(p1.second, p2.second); 133 130 } 134 131 135 int bubble _up(int hole, Pair p) {132 int bubbleUp(int hole, Pair p) { 136 133 int par = parent(hole); 137 134 while( hole>0 && less(p,_data[par]) ) { … … 144 141 } 145 142 146 int bubble _down(int hole, Pair p, int length) {147 int child = second _child(hole);143 int bubbleDown(int hole, Pair p, int length) { 144 int child = secondChild(hole); 148 145 while(child < length) { 149 146 if( less(_data[child1], _data[child]) ) { … … 154 151 move(_data[child], hole); 155 152 hole = child; 156 child = second _child(hole);153 child = secondChild(hole); 157 154 } 158 155 child; … … 172 169 173 170 public: 171 174 172 /// \brief Insert a pair of item and priority into the heap. 175 173 /// 176 /// Adds \c p.first to the heap with priority \c p.second. 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 bubble_up(n, p); 182 } 183 184 /// \brief Insert an item into the heap with the given heap. 185 /// 186 /// Adds \c i to the heap with priority \c p. 181 bubbleUp(n, p); 182 } 183 184 /// \brief Insert an item into the heap with the given priority. 185 /// 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 Returns the item with minimum priority relative to \c Compare. 192 /// 193 /// This method returns the item with minimum priority relative to \c 194 /// Compare. 195 /// \pre The heap must be nonempty. 193 /// \brief Return the item having minimum priority. 194 /// 195 /// This function returns the item having minimum priority. 196 /// \pre The heap must be nonempty. 196 197 Item top() const { 197 198 return _data[0].first; 198 199 } 199 200 200 /// \brief Returns the minimum priority relative to \c Compare.201 /// 202 /// It returns the minimum priority relative to \c Compare.203 /// \pre The heap must be non empty.201 /// \brief The minimum priority. 202 /// 203 /// This function returns the minimum priority. 204 /// \pre The heap must be nonempty. 204 205 Prio prio() const { 205 206 return _data[0].second; 206 207 } 207 208 208 /// \brief Deletes the item with minimum priority relative to \c Compare. 209 /// 210 /// This method deletes the item with minimum priority relative to \c 211 /// Compare from the heap. 209 /// \brief Remove the item having minimum priority. 210 /// 211 /// This function removes the item having minimum priority. 212 212 /// \pre The heap must be nonempty. 213 213 void pop() { … … 215 215 _iim.set(_data[0].first, POST_HEAP); 216 216 if (n > 0) { 217 bubble _down(0, _data[n], n);217 bubbleDown(0, _data[n], n); 218 218 } 219 219 _data.pop_back(); 220 220 } 221 221 222 /// \brief Deletes \c i from the heap. 223 /// 224 /// This method deletes item \c i from the heap. 225 /// \param i The item to erase. 226 /// \pre The item should be in the heap. 222 /// \brief Remove the given item from the heap. 223 /// 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]; … … 230 231 _iim.set(_data[h].first, POST_HEAP); 231 232 if( h < n ) { 232 if ( bubble _up(h, _data[n]) == h) {233 bubble _down(h, _data[n], n);233 if ( bubbleUp(h, _data[n]) == h) { 234 bubbleDown(h, _data[n], n); 234 235 } 235 236 } … … 237 238 } 238 239 239 240 /// \brief Returns the priority of \c i. 241 /// 242 /// This function returns the priority of item \c i. 243 /// \param i The item. 244 /// \pre \c i must be in the heap. 240 /// \brief The priority of the given item. 241 /// 242 /// This function returns the priority of the given item. 243 /// \param i The item. 244 /// \pre \e i must be in the heap. 245 245 Prio operator[](const Item &i) const { 246 246 int idx = _iim[i]; … … 248 248 } 249 249 250 /// \brief \c i gets to the heap with priority \c p independently 251 /// if \c i was already there. 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. 250 /// \brief Set the priority of an item or insert it, if it is 251 /// not stored in the heap. 252 /// 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. … … 261 262 } 262 263 else if( _comp(p, _data[idx].second) ) { 263 bubble _up(idx, Pair(i,p));264 bubbleUp(idx, Pair(i,p)); 264 265 } 265 266 else { 266 bubble _down(idx, Pair(i,p), _data.size());267 } 268 } 269 270 /// \brief Decrease s the priority of \c i to \c p.271 /// 272 /// This method decreases the priority of item \c i to \c p.267 bubbleDown(idx, Pair(i,p), _data.size()); 268 } 269 } 270 271 /// \brief Decrease the priority of an item to the given value. 272 /// 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 bubble _up(idx, Pair(i,p));280 } 281 282 /// \brief Increase s the priority of \c i to \c p.283 /// 284 /// This method sets the priority of item \c i to \c p.279 bubbleUp(idx, Pair(i,p)); 280 } 281 282 /// \brief Increase the priority of an item to the given value. 283 /// 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 bubble _down(idx, Pair(i,p), _data.size());292 } 293 294 /// \brief Return s if \c item is in, has already been in, or has295 /// never been in the heap.296 /// 297 /// This method returns PRE_HEAP if \c item has never been in the298 /// heap, IN_HEAP if it is in the heap at the moment, and POST_HEAP299 /// otherwise. In the latter case it is possible that \c item will300 /// get backto the heap again.290 bubbleDown(idx, Pair(i,p), _data.size()); 291 } 292 293 /// \brief Return the state of an item. 294 /// 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 { … … 307 306 } 308 307 309 /// \brief Set s the state of the \citem in the heap.310 /// 311 /// Sets the state of the \c item in the heap. It can be used to312 /// manually clear the heap when it is important to achive the313 /// better time complexity.308 /// \brief Set the state of an item in the heap. 309 /// 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. … … 328 327 } 329 328 330 /// \brief Replaces an item in the heap. 331 /// 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. 329 /// \brief Replace an item in the heap. 330 /// 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];
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