1.1 --- a/lemon/bin_heap.h Fri Jul 24 11:07:52 2009 +0200
1.2 +++ b/lemon/bin_heap.h Fri Sep 25 09:06:32 2009 +0200
1.3 @@ -19,9 +19,9 @@
1.4 #ifndef LEMON_BIN_HEAP_H
1.5 #define LEMON_BIN_HEAP_H
1.6
1.7 -///\ingroup auxdat
1.8 +///\ingroup heaps
1.9 ///\file
1.10 -///\brief Binary Heap implementation.
1.11 +///\brief Binary heap implementation.
1.12
1.13 #include <vector>
1.14 #include <utility>
1.15 @@ -29,45 +29,41 @@
1.16
1.17 namespace lemon {
1.18
1.19 - ///\ingroup auxdat
1.20 + /// \ingroup heaps
1.21 ///
1.22 - ///\brief A Binary Heap implementation.
1.23 + /// \brief Binary heap data structure.
1.24 ///
1.25 - ///This class implements the \e binary \e heap data structure.
1.26 + /// This class implements the \e binary \e heap data structure.
1.27 + /// It fully conforms to the \ref concepts::Heap "heap concept".
1.28 ///
1.29 - ///A \e heap is a data structure for storing items with specified values
1.30 - ///called \e priorities in such a way that finding the item with minimum
1.31 - ///priority is efficient. \c CMP specifies the ordering of the priorities.
1.32 - ///In a heap one can change the priority of an item, add or erase an
1.33 - ///item, etc.
1.34 - ///
1.35 - ///\tparam PR Type of the priority of the items.
1.36 - ///\tparam IM A read and writable item map with int values, used internally
1.37 - ///to handle the cross references.
1.38 - ///\tparam CMP A functor class for the ordering of the priorities.
1.39 - ///The default is \c std::less<PR>.
1.40 - ///
1.41 - ///\sa FibHeap
1.42 - ///\sa Dijkstra
1.43 + /// \tparam PR Type of the priorities of the items.
1.44 + /// \tparam IM A read-writable item map with \c int values, used
1.45 + /// internally to handle the cross references.
1.46 + /// \tparam CMP A functor class for comparing the priorities.
1.47 + /// The default is \c std::less<PR>.
1.48 +#ifdef DOXYGEN
1.49 + template <typename PR, typename IM, typename CMP>
1.50 +#else
1.51 template <typename PR, typename IM, typename CMP = std::less<PR> >
1.52 +#endif
1.53 class BinHeap {
1.54 + public:
1.55
1.56 - public:
1.57 - ///\e
1.58 + /// Type of the item-int map.
1.59 typedef IM ItemIntMap;
1.60 - ///\e
1.61 + /// Type of the priorities.
1.62 typedef PR Prio;
1.63 - ///\e
1.64 + /// Type of the items stored in the heap.
1.65 typedef typename ItemIntMap::Key Item;
1.66 - ///\e
1.67 + /// Type of the item-priority pairs.
1.68 typedef std::pair<Item,Prio> Pair;
1.69 - ///\e
1.70 + /// Functor type for comparing the priorities.
1.71 typedef CMP Compare;
1.72
1.73 - /// \brief Type to represent the items states.
1.74 + /// \brief Type to represent the states of the items.
1.75 ///
1.76 - /// Each Item element have a state associated to it. It may be "in heap",
1.77 - /// "pre heap" or "post heap". The latter two are indifferent from the
1.78 + /// Each item has a state associated to it. It can be "in heap",
1.79 + /// "pre-heap" or "post-heap". The latter two are indifferent from the
1.80 /// heap's point of view, but may be useful to the user.
1.81 ///
1.82 /// The item-int map must be initialized in such way that it assigns
1.83 @@ -84,42 +80,43 @@
1.84 ItemIntMap &_iim;
1.85
1.86 public:
1.87 - /// \brief The constructor.
1.88 +
1.89 + /// \brief Constructor.
1.90 ///
1.91 - /// The constructor.
1.92 - /// \param map should be given to the constructor, since it is used
1.93 - /// internally to handle the cross references. The value of the map
1.94 - /// must be \c PRE_HEAP (<tt>-1</tt>) for every item.
1.95 + /// Constructor.
1.96 + /// \param map A map that assigns \c int values to the items.
1.97 + /// It is used internally to handle the cross references.
1.98 + /// The assigned value must be \c PRE_HEAP (<tt>-1</tt>) for each item.
1.99 explicit BinHeap(ItemIntMap &map) : _iim(map) {}
1.100
1.101 - /// \brief The constructor.
1.102 + /// \brief Constructor.
1.103 ///
1.104 - /// The constructor.
1.105 - /// \param map should be given to the constructor, since it is used
1.106 - /// internally to handle the cross references. The value of the map
1.107 - /// should be PRE_HEAP (-1) for each element.
1.108 - ///
1.109 - /// \param comp The comparator function object.
1.110 + /// Constructor.
1.111 + /// \param map A map that assigns \c int values to the items.
1.112 + /// It is used internally to handle the cross references.
1.113 + /// The assigned value must be \c PRE_HEAP (<tt>-1</tt>) for each item.
1.114 + /// \param comp The function object used for comparing the priorities.
1.115 BinHeap(ItemIntMap &map, const Compare &comp)
1.116 : _iim(map), _comp(comp) {}
1.117
1.118
1.119 - /// The number of items stored in the heap.
1.120 + /// \brief The number of items stored in the heap.
1.121 ///
1.122 - /// \brief Returns the number of items stored in the heap.
1.123 + /// This function returns the number of items stored in the heap.
1.124 int size() const { return _data.size(); }
1.125
1.126 - /// \brief Checks if the heap stores no items.
1.127 + /// \brief Check if the heap is empty.
1.128 ///
1.129 - /// Returns \c true if and only if the heap stores no items.
1.130 + /// This function returns \c true if the heap is empty.
1.131 bool empty() const { return _data.empty(); }
1.132
1.133 - /// \brief Make empty this heap.
1.134 + /// \brief Make the heap empty.
1.135 ///
1.136 - /// Make empty this heap. It does not change the cross reference map.
1.137 - /// If you want to reuse what is not surely empty you should first clear
1.138 - /// the heap and after that you should set the cross reference map for
1.139 - /// each item to \c PRE_HEAP.
1.140 + /// This functon makes the heap empty.
1.141 + /// It does not change the cross reference map. If you want to reuse
1.142 + /// a heap that is not surely empty, you should first clear it and
1.143 + /// then you should set the cross reference map to \c PRE_HEAP
1.144 + /// for each item.
1.145 void clear() {
1.146 _data.clear();
1.147 }
1.148 @@ -127,12 +124,12 @@
1.149 private:
1.150 static int parent(int i) { return (i-1)/2; }
1.151
1.152 - static int second_child(int i) { return 2*i+2; }
1.153 + static int secondChild(int i) { return 2*i+2; }
1.154 bool less(const Pair &p1, const Pair &p2) const {
1.155 return _comp(p1.second, p2.second);
1.156 }
1.157
1.158 - int bubble_up(int hole, Pair p) {
1.159 + int bubbleUp(int hole, Pair p) {
1.160 int par = parent(hole);
1.161 while( hole>0 && less(p,_data[par]) ) {
1.162 move(_data[par],hole);
1.163 @@ -143,8 +140,8 @@
1.164 return hole;
1.165 }
1.166
1.167 - int bubble_down(int hole, Pair p, int length) {
1.168 - int child = second_child(hole);
1.169 + int bubbleDown(int hole, Pair p, int length) {
1.170 + int child = secondChild(hole);
1.171 while(child < length) {
1.172 if( less(_data[child-1], _data[child]) ) {
1.173 --child;
1.174 @@ -153,7 +150,7 @@
1.175 goto ok;
1.176 move(_data[child], hole);
1.177 hole = child;
1.178 - child = second_child(hole);
1.179 + child = secondChild(hole);
1.180 }
1.181 child--;
1.182 if( child<length && less(_data[child], p) ) {
1.183 @@ -171,87 +168,91 @@
1.184 }
1.185
1.186 public:
1.187 +
1.188 /// \brief Insert a pair of item and priority into the heap.
1.189 ///
1.190 - /// Adds \c p.first to the heap with priority \c p.second.
1.191 + /// This function inserts \c p.first to the heap with priority
1.192 + /// \c p.second.
1.193 /// \param p The pair to insert.
1.194 + /// \pre \c p.first must not be stored in the heap.
1.195 void push(const Pair &p) {
1.196 int n = _data.size();
1.197 _data.resize(n+1);
1.198 - bubble_up(n, p);
1.199 + bubbleUp(n, p);
1.200 }
1.201
1.202 - /// \brief Insert an item into the heap with the given heap.
1.203 + /// \brief Insert an item into the heap with the given priority.
1.204 ///
1.205 - /// Adds \c i to the heap with priority \c p.
1.206 + /// This function inserts the given item into the heap with the
1.207 + /// given priority.
1.208 /// \param i The item to insert.
1.209 /// \param p The priority of the item.
1.210 + /// \pre \e i must not be stored in the heap.
1.211 void push(const Item &i, const Prio &p) { push(Pair(i,p)); }
1.212
1.213 - /// \brief Returns the item with minimum priority relative to \c Compare.
1.214 + /// \brief Return the item having minimum priority.
1.215 ///
1.216 - /// This method returns the item with minimum priority relative to \c
1.217 - /// Compare.
1.218 - /// \pre The heap must be nonempty.
1.219 + /// This function returns the item having minimum priority.
1.220 + /// \pre The heap must be non-empty.
1.221 Item top() const {
1.222 return _data[0].first;
1.223 }
1.224
1.225 - /// \brief Returns the minimum priority relative to \c Compare.
1.226 + /// \brief The minimum priority.
1.227 ///
1.228 - /// It returns the minimum priority relative to \c Compare.
1.229 - /// \pre The heap must be nonempty.
1.230 + /// This function returns the minimum priority.
1.231 + /// \pre The heap must be non-empty.
1.232 Prio prio() const {
1.233 return _data[0].second;
1.234 }
1.235
1.236 - /// \brief Deletes the item with minimum priority relative to \c Compare.
1.237 + /// \brief Remove the item having minimum priority.
1.238 ///
1.239 - /// This method deletes the item with minimum priority relative to \c
1.240 - /// Compare from the heap.
1.241 + /// This function removes the item having minimum priority.
1.242 /// \pre The heap must be non-empty.
1.243 void pop() {
1.244 int n = _data.size()-1;
1.245 _iim.set(_data[0].first, POST_HEAP);
1.246 if (n > 0) {
1.247 - bubble_down(0, _data[n], n);
1.248 + bubbleDown(0, _data[n], n);
1.249 }
1.250 _data.pop_back();
1.251 }
1.252
1.253 - /// \brief Deletes \c i from the heap.
1.254 + /// \brief Remove the given item from the heap.
1.255 ///
1.256 - /// This method deletes item \c i from the heap.
1.257 - /// \param i The item to erase.
1.258 - /// \pre The item should be in the heap.
1.259 + /// This function removes the given item from the heap if it is
1.260 + /// already stored.
1.261 + /// \param i The item to delete.
1.262 + /// \pre \e i must be in the heap.
1.263 void erase(const Item &i) {
1.264 int h = _iim[i];
1.265 int n = _data.size()-1;
1.266 _iim.set(_data[h].first, POST_HEAP);
1.267 if( h < n ) {
1.268 - if ( bubble_up(h, _data[n]) == h) {
1.269 - bubble_down(h, _data[n], n);
1.270 + if ( bubbleUp(h, _data[n]) == h) {
1.271 + bubbleDown(h, _data[n], n);
1.272 }
1.273 }
1.274 _data.pop_back();
1.275 }
1.276
1.277 -
1.278 - /// \brief Returns the priority of \c i.
1.279 + /// \brief The priority of the given item.
1.280 ///
1.281 - /// This function returns the priority of item \c i.
1.282 + /// This function returns the priority of the given item.
1.283 /// \param i The item.
1.284 - /// \pre \c i must be in the heap.
1.285 + /// \pre \e i must be in the heap.
1.286 Prio operator[](const Item &i) const {
1.287 int idx = _iim[i];
1.288 return _data[idx].second;
1.289 }
1.290
1.291 - /// \brief \c i gets to the heap with priority \c p independently
1.292 - /// if \c i was already there.
1.293 + /// \brief Set the priority of an item or insert it, if it is
1.294 + /// not stored in the heap.
1.295 ///
1.296 - /// This method calls \ref push(\c i, \c p) if \c i is not stored
1.297 - /// in the heap and sets the priority of \c i to \c p otherwise.
1.298 + /// This method sets the priority of the given item if it is
1.299 + /// already stored in the heap. Otherwise it inserts the given
1.300 + /// item into the heap with the given priority.
1.301 /// \param i The item.
1.302 /// \param p The priority.
1.303 void set(const Item &i, const Prio &p) {
1.304 @@ -260,44 +261,42 @@
1.305 push(i,p);
1.306 }
1.307 else if( _comp(p, _data[idx].second) ) {
1.308 - bubble_up(idx, Pair(i,p));
1.309 + bubbleUp(idx, Pair(i,p));
1.310 }
1.311 else {
1.312 - bubble_down(idx, Pair(i,p), _data.size());
1.313 + bubbleDown(idx, Pair(i,p), _data.size());
1.314 }
1.315 }
1.316
1.317 - /// \brief Decreases the priority of \c i to \c p.
1.318 + /// \brief Decrease the priority of an item to the given value.
1.319 ///
1.320 - /// This method decreases the priority of item \c i to \c p.
1.321 + /// This function decreases the priority of an item to the given value.
1.322 /// \param i The item.
1.323 /// \param p The priority.
1.324 - /// \pre \c i must be stored in the heap with priority at least \c
1.325 - /// p relative to \c Compare.
1.326 + /// \pre \e i must be stored in the heap with priority at least \e p.
1.327 void decrease(const Item &i, const Prio &p) {
1.328 int idx = _iim[i];
1.329 - bubble_up(idx, Pair(i,p));
1.330 + bubbleUp(idx, Pair(i,p));
1.331 }
1.332
1.333 - /// \brief Increases the priority of \c i to \c p.
1.334 + /// \brief Increase the priority of an item to the given value.
1.335 ///
1.336 - /// This method sets the priority of item \c i to \c p.
1.337 + /// This function increases the priority of an item to the given value.
1.338 /// \param i The item.
1.339 /// \param p The priority.
1.340 - /// \pre \c i must be stored in the heap with priority at most \c
1.341 - /// p relative to \c Compare.
1.342 + /// \pre \e i must be stored in the heap with priority at most \e p.
1.343 void increase(const Item &i, const Prio &p) {
1.344 int idx = _iim[i];
1.345 - bubble_down(idx, Pair(i,p), _data.size());
1.346 + bubbleDown(idx, Pair(i,p), _data.size());
1.347 }
1.348
1.349 - /// \brief Returns if \c item is in, has already been in, or has
1.350 - /// never been in the heap.
1.351 + /// \brief Return the state of an item.
1.352 ///
1.353 - /// This method returns PRE_HEAP if \c item has never been in the
1.354 - /// heap, IN_HEAP if it is in the heap at the moment, and POST_HEAP
1.355 - /// otherwise. In the latter case it is possible that \c item will
1.356 - /// get back to the heap again.
1.357 + /// This method returns \c PRE_HEAP if the given item has never
1.358 + /// been in the heap, \c IN_HEAP if it is in the heap at the moment,
1.359 + /// and \c POST_HEAP otherwise.
1.360 + /// In the latter case it is possible that the item will get back
1.361 + /// to the heap again.
1.362 /// \param i The item.
1.363 State state(const Item &i) const {
1.364 int s = _iim[i];
1.365 @@ -306,11 +305,11 @@
1.366 return State(s);
1.367 }
1.368
1.369 - /// \brief Sets the state of the \c item in the heap.
1.370 + /// \brief Set the state of an item in the heap.
1.371 ///
1.372 - /// Sets the state of the \c item in the heap. It can be used to
1.373 - /// manually clear the heap when it is important to achive the
1.374 - /// better time complexity.
1.375 + /// This function sets the state of the given item in the heap.
1.376 + /// It can be used to manually clear the heap when it is important
1.377 + /// to achive better time complexity.
1.378 /// \param i The item.
1.379 /// \param st The state. It should not be \c IN_HEAP.
1.380 void state(const Item& i, State st) {
1.381 @@ -327,12 +326,13 @@
1.382 }
1.383 }
1.384
1.385 - /// \brief Replaces an item in the heap.
1.386 + /// \brief Replace an item in the heap.
1.387 ///
1.388 - /// The \c i item is replaced with \c j item. The \c i item should
1.389 - /// be in the heap, while the \c j should be out of the heap. The
1.390 - /// \c i item will out of the heap and \c j will be in the heap
1.391 - /// with the same prioriority as prevoiusly the \c i item.
1.392 + /// This function replaces item \c i with item \c j.
1.393 + /// Item \c i must be in the heap, while \c j must be out of the heap.
1.394 + /// After calling this method, item \c i will be out of the
1.395 + /// heap and \c j will be in the heap with the same prioriority
1.396 + /// as item \c i had before.
1.397 void replace(const Item& i, const Item& j) {
1.398 int idx = _iim[i];
1.399 _iim.set(i, _iim[j]);