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| ... | ... |
@@ -223,33 +223,54 @@ |
| 223 | 223 |
the two maps which can be done implicitly with the \c DivMap template |
| 224 | 224 |
class. We use the implicit minimum time map as the length map of the |
| 225 | 225 |
\c Dijkstra algorithm. |
| 226 | 226 |
*/ |
| 227 | 227 |
|
| 228 | 228 |
/** |
| 229 |
@defgroup matrices Matrices |
|
| 230 |
@ingroup datas |
|
| 231 |
\brief Two dimensional data storages implemented in LEMON. |
|
| 232 |
|
|
| 233 |
This group contains two dimensional data storages implemented in LEMON. |
|
| 234 |
*/ |
|
| 235 |
|
|
| 236 |
/** |
|
| 237 | 229 |
@defgroup paths Path Structures |
| 238 | 230 |
@ingroup datas |
| 239 | 231 |
\brief %Path structures implemented in LEMON. |
| 240 | 232 |
|
| 241 | 233 |
This group contains the path structures implemented in LEMON. |
| 242 | 234 |
|
| 243 | 235 |
LEMON provides flexible data structures to work with paths. |
| 244 | 236 |
All of them have similar interfaces and they can be copied easily with |
| 245 | 237 |
assignment operators and copy constructors. This makes it easy and |
| 246 | 238 |
efficient to have e.g. the Dijkstra algorithm to store its result in |
| 247 | 239 |
any kind of path structure. |
| 248 | 240 |
|
| 249 |
\sa |
|
| 241 |
\sa \ref concepts::Path "Path concept" |
|
| 242 |
*/ |
|
| 243 |
|
|
| 244 |
/** |
|
| 245 |
@defgroup heaps Heap Structures |
|
| 246 |
@ingroup datas |
|
| 247 |
\brief %Heap structures implemented in LEMON. |
|
| 248 |
|
|
| 249 |
This group contains the heap structures implemented in LEMON. |
|
| 250 |
|
|
| 251 |
LEMON provides several heap classes. They are efficient implementations |
|
| 252 |
of the abstract data type \e priority \e queue. They store items with |
|
| 253 |
specified values called \e priorities in such a way that finding and |
|
| 254 |
removing the item with minimum priority are efficient. |
|
| 255 |
The basic operations are adding and erasing items, changing the priority |
|
| 256 |
of an item, etc. |
|
| 257 |
|
|
| 258 |
Heaps are crucial in several algorithms, such as Dijkstra and Prim. |
|
| 259 |
The heap implementations have the same interface, thus any of them can be |
|
| 260 |
used easily in such algorithms. |
|
| 261 |
|
|
| 262 |
\sa \ref concepts::Heap "Heap concept" |
|
| 263 |
*/ |
|
| 264 |
|
|
| 265 |
/** |
|
| 266 |
@defgroup matrices Matrices |
|
| 267 |
@ingroup datas |
|
| 268 |
\brief Two dimensional data storages implemented in LEMON. |
|
| 269 |
|
|
| 270 |
This group contains two dimensional data storages implemented in LEMON. |
|
| 250 | 271 |
*/ |
| 251 | 272 |
|
| 252 | 273 |
/** |
| 253 | 274 |
@defgroup auxdat Auxiliary Data Structures |
| 254 | 275 |
@ingroup datas |
| 255 | 276 |
\brief Auxiliary data structures implemented in LEMON. |
| ... | ... |
@@ -16,61 +16,57 @@ |
| 16 | 16 |
* |
| 17 | 17 |
*/ |
| 18 | 18 |
|
| 19 | 19 |
#ifndef LEMON_BIN_HEAP_H |
| 20 | 20 |
#define LEMON_BIN_HEAP_H |
| 21 | 21 |
|
| 22 |
///\ingroup |
|
| 22 |
///\ingroup heaps |
|
| 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 |
|
| 32 |
/// \ingroup heaps |
|
| 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. |
| ... | ... |
@@ -81,82 +77,83 @@ |
| 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; }
|
| 129 | 126 |
|
| 130 |
static int |
|
| 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 |
|
| 132 |
int bubbleUp(int hole, Pair p) {
|
|
| 136 | 133 |
int par = parent(hole); |
| 137 | 134 |
while( hole>0 && less(p,_data[par]) ) {
|
| 138 | 135 |
move(_data[par],hole); |
| 139 | 136 |
hole = par; |
| 140 | 137 |
par = parent(hole); |
| 141 | 138 |
} |
| 142 | 139 |
move(p, hole); |
| 143 | 140 |
return hole; |
| 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[child-1], _data[child]) ) {
|
| 150 | 147 |
--child; |
| 151 | 148 |
} |
| 152 | 149 |
if( !less(_data[child], p) ) |
| 153 | 150 |
goto ok; |
| 154 | 151 |
move(_data[child], hole); |
| 155 | 152 |
hole = child; |
| 156 |
child = |
|
| 153 |
child = secondChild(hole); |
|
| 157 | 154 |
} |
| 158 | 155 |
child--; |
| 159 | 156 |
if( child<length && less(_data[child], p) ) {
|
| 160 | 157 |
move(_data[child], hole); |
| 161 | 158 |
hole=child; |
| 162 | 159 |
} |
| ... | ... |
@@ -168,152 +165,154 @@ |
| 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 |
bubbleUp(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 |
bubbleDown(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 |
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 |
} |
| 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); |
| 261 | 262 |
} |
| 262 | 263 |
else if( _comp(p, _data[idx].second) ) {
|
| 263 |
|
|
| 264 |
bubbleUp(idx, Pair(i,p)); |
|
| 264 | 265 |
} |
| 265 | 266 |
else {
|
| 266 |
|
|
| 267 |
bubbleDown(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 |
bubbleUp(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 |
bubbleDown(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 |
} |
| ... | ... |
@@ -16,15 +16,15 @@ |
| 16 | 16 |
* |
| 17 | 17 |
*/ |
| 18 | 18 |
|
| 19 | 19 |
#ifndef LEMON_BUCKET_HEAP_H |
| 20 | 20 |
#define LEMON_BUCKET_HEAP_H |
| 21 | 21 |
|
| 22 |
///\ingroup |
|
| 22 |
///\ingroup heaps |
|
| 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 {
|
| ... | ... |
@@ -50,94 +50,102 @@ |
| 50 | 50 |
--value; |
| 51 | 51 |
} |
| 52 | 52 |
}; |
| 53 | 53 |
|
| 54 | 54 |
} |
| 55 | 55 |
|
| 56 |
/// \ingroup |
|
| 56 |
/// \ingroup heaps |
|
| 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 |
|
| 137 |
void |
|
| 145 |
void relocateLast(int idx) {
|
|
| 138 | 146 |
if (idx + 1 < int(_data.size())) {
|
| 139 | 147 |
_data[idx] = _data.back(); |
| 140 | 148 |
if (_data[idx].prev != -1) {
|
| 141 | 149 |
_data[_data[idx].prev].next = idx; |
| 142 | 150 |
} else {
|
| 143 | 151 |
_first[_data[idx].value] = idx; |
| ... | ... |
@@ -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 |
relocateLast(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 |
relocateLast(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: |
| ... | ... |
@@ -356,104 +368,120 @@ |
| 356 | 368 |
std::vector<int> _first; |
| 357 | 369 |
std::vector<BucketItem> _data; |
| 358 | 370 |
mutable int _minimum; |
| 359 | 371 |
|
| 360 | 372 |
}; // class BucketHeap |
| 361 | 373 |
|
| 362 |
/// \ingroup |
|
| 374 |
/// \ingroup heaps |
|
| 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 \ref heaps "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> |
| ... | ... |
@@ -17,59 +17,55 @@ |
| 17 | 17 |
*/ |
| 18 | 18 |
|
| 19 | 19 |
#ifndef LEMON_FIB_HEAP_H |
| 20 | 20 |
#define LEMON_FIB_HEAP_H |
| 21 | 21 |
|
| 22 | 22 |
///\file |
| 23 |
///\ingroup auxdat |
|
| 24 |
///\brief Fibonacci Heap implementation. |
|
| 23 |
///\ingroup heaps |
|
| 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 |
/// \ingroup |
|
| 33 |
/// \ingroup heaps |
|
| 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; |
| ... | ... |
@@ -165,82 +155,74 @@ |
| 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 ) {
|
| 211 |
|
|
| 191 |
makeRoot(_data[_minimum].child); |
|
| 212 | 192 |
_minimum=_data[_minimum].child; |
| 213 | 193 |
balance(); |
| 214 | 194 |
} |
| 215 | 195 |
} else {
|
| 216 | 196 |
int right=_data[_minimum].right_neighbor; |
| 217 | 197 |
unlace(_minimum); |
| 218 | 198 |
_data[_minimum].in=false; |
| 219 | 199 |
if ( _data[_minimum].degree > 0 ) {
|
| 220 | 200 |
int left=_data[_minimum].left_neighbor; |
| 221 | 201 |
int child=_data[_minimum].child; |
| 222 | 202 |
int last_child=_data[child].left_neighbor; |
| 223 | 203 |
|
| 224 |
|
|
| 204 |
makeRoot(child); |
|
| 225 | 205 |
|
| 226 | 206 |
_data[left].right_neighbor=child; |
| 227 | 207 |
_data[child].left_neighbor=left; |
| 228 | 208 |
_data[right].left_neighbor=last_child; |
| 229 | 209 |
_data[last_child].right_neighbor=right; |
| 230 | 210 |
} |
| 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: |
| ... | ... |
@@ -362,13 +369,13 @@ |
| 362 | 369 |
do {
|
| 363 | 370 |
if ( _comp(_data[s].prio, _data[_minimum].prio) ) _minimum=s; |
| 364 | 371 |
s=_data[s].right_neighbor; |
| 365 | 372 |
} while ( s != m ); |
| 366 | 373 |
} |
| 367 | 374 |
|
| 368 |
void |
|
| 375 |
void makeRoot(int c) {
|
|
| 369 | 376 |
int s=c; |
| 370 | 377 |
do {
|
| 371 | 378 |
_data[s].parent=-1; |
| 372 | 379 |
s=_data[s].right_neighbor; |
| 373 | 380 |
} while ( s != c ); |
| 374 | 381 |
} |
| ... | ... |
@@ -16,72 +16,70 @@ |
| 16 | 16 |
* |
| 17 | 17 |
*/ |
| 18 | 18 |
|
| 19 | 19 |
#ifndef LEMON_RADIX_HEAP_H |
| 20 | 20 |
#define LEMON_RADIX_HEAP_H |
| 21 | 21 |
|
| 22 |
///\ingroup |
|
| 22 |
///\ingroup heaps |
|
| 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 heaps |
|
| 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 |
class UnderFlowPriorityError : public Exception {
|
|
| 61 |
class PriorityUnderflowError : public Exception {
|
|
| 64 | 62 |
public: |
| 65 | 63 |
virtual const char* what() const throw() {
|
| 66 |
return "lemon::RadixHeap:: |
|
| 64 |
return "lemon::RadixHeap::PriorityUnderflowError"; |
|
| 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; |
| ... | ... |
@@ -93,326 +91,333 @@ |
| 93 | 91 |
struct RadixBox {
|
| 94 | 92 |
int first; |
| 95 | 93 |
int min, size; |
| 96 | 94 |
RadixBox(int _min, int _size) : first(-1), min(_min), size(_size) {}
|
| 97 | 95 |
}; |
| 98 | 96 |
|
| 99 |
std::vector<RadixItem> data; |
|
| 100 |
std::vector<RadixBox> boxes; |
|
| 97 |
std::vector<RadixItem> _data; |
|
| 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 |
/// \brief Returns the number of items stored in the heap. |
|
| 128 |
int size() const { return data.size(); }
|
|
| 129 |
/// |
|
| 124 |
/// This function returns the number of items stored in the heap. |
|
| 125 |
int size() const { return _data.size(); }
|
|
| 126 |
|
|
| 127 |
/// \brief Check if the heap is empty. |
|
| 130 | 128 |
/// |
| 131 |
/// Returns \c true if and only if the heap stores no items. |
|
| 132 |
bool empty() const { return data.empty(); }
|
|
| 129 |
/// This function returns \c true if the heap is empty. |
|
| 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 |
void clear(int minimal = 0, int capacity = 0) {
|
|
| 141 |
data.clear(); boxes.clear(); |
|
| 142 |
boxes.push_back(RadixBox(minimal, 1)); |
|
| 143 |
boxes.push_back(RadixBox(minimal + 1, 1)); |
|
| 144 |
|
|
| 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) {
|
|
| 142 |
_data.clear(); _boxes.clear(); |
|
| 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 |
|
| 151 | 152 |
bool upper(int box, Prio pr) {
|
| 152 |
return pr < |
|
| 153 |
return pr < _boxes[box].min; |
|
| 153 | 154 |
} |
| 154 | 155 |
|
| 155 | 156 |
bool lower(int box, Prio pr) {
|
| 156 |
return pr >= |
|
| 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 |
if (data[index].prev >= 0) {
|
|
| 162 |
data[data[index].prev].next = data[index].next; |
|
| 162 |
if (_data[index].prev >= 0) {
|
|
| 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 |
if (data[index].next >= 0) {
|
|
| 167 |
data[data[index].next].prev = data[index].prev; |
|
| 167 |
if (_data[index].next >= 0) {
|
|
| 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 |
if (boxes[box].first == -1) {
|
|
| 174 |
boxes[box].first = index; |
|
| 175 |
|
|
| 174 |
if (_boxes[box].first == -1) {
|
|
| 175 |
_boxes[box].first = index; |
|
| 176 |
_data[index].next = _data[index].prev = -1; |
|
| 176 | 177 |
} else {
|
| 177 |
data[index].next = boxes[box].first; |
|
| 178 |
data[boxes[box].first].prev = index; |
|
| 179 |
data[index].prev = -1; |
|
| 180 |
boxes[box].first = index; |
|
| 178 |
_data[index].next = _boxes[box].first; |
|
| 179 |
_data[_boxes[box].first].prev = index; |
|
| 180 |
_data[index].prev = -1; |
|
| 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 |
int min = boxes.back().min + boxes.back().size; |
|
| 188 |
int bs = 2 * boxes.back().size; |
|
| 189 |
|
|
| 188 |
int min = _boxes.back().min + _boxes.back().size; |
|
| 189 |
int bs = 2 * _boxes.back().size; |
|
| 190 |
_boxes.push_back(RadixBox(min, bs)); |
|
| 190 | 191 |
} |
| 191 | 192 |
|
| 192 |
/// \brief Move an item up into the proper box. |
|
| 193 |
void bubble_up(int index) {
|
|
| 194 |
|
|
| 193 |
// Move an item up into the proper box. |
|
| 194 |
void bubbleUp(int index) {
|
|
| 195 |
if (!lower(_data[index].box, _data[index].prio)) return; |
|
| 195 | 196 |
remove(index); |
| 196 |
int box = findUp( |
|
| 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 |
if (++start == int( |
|
| 204 |
if (++start == int(_boxes.size())) {
|
|
| 204 | 205 |
extend(); |
| 205 | 206 |
} |
| 206 | 207 |
} |
| 207 | 208 |
return start; |
| 208 | 209 |
} |
| 209 | 210 |
|
| 210 |
/// \brief Move an item down into the proper box. |
|
| 211 |
void bubble_down(int index) {
|
|
| 212 |
|
|
| 211 |
// Move an item down into the proper box |
|
| 212 |
void bubbleDown(int index) {
|
|
| 213 |
if (!upper(_data[index].box, _data[index].prio)) return; |
|
| 213 | 214 |
remove(index); |
| 214 |
int box = findDown( |
|
| 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 |
if (--start < 0) throw |
|
| 222 |
if (--start < 0) throw PriorityUnderflowError(); |
|
| 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 |
while ( |
|
| 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 |
int min = data[boxes[box].first].prio; |
|
| 236 |
for (int k = boxes[box].first; k != -1; k = data[k].next) {
|
|
| 237 |
|
|
| 236 |
int min = _data[_boxes[box].first].prio; |
|
| 237 |
for (int k = _boxes[box].first; k != -1; k = _data[k].next) {
|
|
| 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 |
boxes[i].min = min; |
|
| 250 |
min += boxes[i].size; |
|
| 249 |
_boxes[i].min = min; |
|
| 250 |
min += _boxes[i].size; |
|
| 251 | 251 |
} |
| 252 |
int curr = |
|
| 252 |
int curr = _boxes[box].first, next; |
|
| 253 | 253 |
while (curr != -1) {
|
| 254 |
next = data[curr].next; |
|
| 255 |
bubble_down(curr); |
|
| 254 |
next = _data[curr].next; |
|
| 255 |
bubbleDown(curr); |
|
| 256 | 256 |
curr = next; |
| 257 | 257 |
} |
| 258 | 258 |
} |
| 259 | 259 |
|
| 260 |
void relocate_last(int index) {
|
|
| 261 |
if (index != int(data.size()) - 1) {
|
|
| 262 |
data[index] = data.back(); |
|
| 263 |
if (data[index].prev != -1) {
|
|
| 264 |
|
|
| 260 |
void relocateLast(int index) {
|
|
| 261 |
if (index != int(_data.size()) - 1) {
|
|
| 262 |
_data[index] = _data.back(); |
|
| 263 |
if (_data[index].prev != -1) {
|
|
| 264 |
_data[_data[index].prev].next = index; |
|
| 265 | 265 |
} else {
|
| 266 |
|
|
| 266 |
_boxes[_data[index].box].first = index; |
|
| 267 | 267 |
} |
| 268 |
if (data[index].next != -1) {
|
|
| 269 |
data[data[index].next].prev = index; |
|
| 268 |
if (_data[index].next != -1) {
|
|
| 269 |
_data[_data[index].next].prev = index; |
|
| 270 | 270 |
} |
| 271 |
_iim[ |
|
| 271 |
_iim[_data[index].item] = index; |
|
| 272 | 272 |
} |
| 273 |
|
|
| 273 |
_data.pop_back(); |
|
| 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 |
int n = |
|
| 287 |
int n = _data.size(); |
|
| 285 | 288 |
_iim.set(i, n); |
| 286 |
data.push_back(RadixItem(i, p)); |
|
| 287 |
while (lower(boxes.size() - 1, p)) {
|
|
| 289 |
_data.push_back(RadixItem(i, p)); |
|
| 290 |
while (lower(_boxes.size() - 1, p)) {
|
|
| 288 | 291 |
extend(); |
| 289 | 292 |
} |
| 290 |
int box = findDown( |
|
| 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. |
|
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/// \pre The heap must be nonempty. |
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/// This function returns the item having minimum priority. |
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/// \pre The heap must be non-empty. |
|
| 298 | 301 |
Item top() const {
|
| 299 | 302 |
const_cast<RadixHeap<ItemIntMap>&>(*this).moveDown(); |
| 300 |
return |
|
| 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. |
|
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/// This function returns the minimum priority. |
|
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/// \pre The heap must be non-empty. |
|
| 307 | 310 |
Prio prio() const {
|
| 308 | 311 |
const_cast<RadixHeap<ItemIntMap>&>(*this).moveDown(); |
| 309 |
return |
|
| 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 |
int index = boxes[0].first; |
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_iim[data[index].item] = POST_HEAP; |
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int index = _boxes[0].first; |
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_iim[_data[index].item] = POST_HEAP; |
|
| 320 | 323 |
remove(index); |
| 321 |
|
|
| 324 |
relocateLast(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 |
relocateLast(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 |
return |
|
| 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 |
else if( p >= data[idx].prio ) {
|
|
| 360 |
data[idx].prio = p; |
|
| 361 |
|
|
| 365 |
else if( p >= _data[idx].prio ) {
|
|
| 366 |
_data[idx].prio = p; |
|
| 367 |
bubbleUp(idx); |
|
| 362 | 368 |
} else {
|
| 363 |
data[idx].prio = p; |
|
| 364 |
bubble_down(idx); |
|
| 369 |
_data[idx].prio = p; |
|
| 370 |
bubbleDown(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 |
data[idx].prio = p; |
|
| 379 |
bubble_down(idx); |
|
| 383 |
_data[idx].prio = p; |
|
| 384 |
bubbleDown(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 |
data[idx].prio = p; |
|
| 391 |
bubble_up(idx); |
|
| 395 |
_data[idx].prio = p; |
|
| 396 |
bubbleUp(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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