1.1 --- a/lemon/fib_heap.h Thu Jun 11 22:16:11 2009 +0200
1.2 +++ b/lemon/fib_heap.h Thu Jun 11 23:13:24 2009 +0200
1.3 @@ -36,87 +36,88 @@
1.4 ///This class implements the \e Fibonacci \e heap data structure. A \e heap
1.5 ///is a data structure for storing items with specified values called \e
1.6 ///priorities in such a way that finding the item with minimum priority is
1.7 - ///efficient. \c Compare specifies the ordering of the priorities. In a heap
1.8 + ///efficient. \c CMP specifies the ordering of the priorities. In a heap
1.9 ///one can change the priority of an item, add or erase an item, etc.
1.10 ///
1.11 ///The methods \ref increase and \ref erase are not efficient in a Fibonacci
1.12 ///heap. In case of many calls to these operations, it is better to use a
1.13 ///\ref BinHeap "binary heap".
1.14 ///
1.15 - ///\param _Prio Type of the priority of the items.
1.16 - ///\param _ItemIntMap A read and writable Item int map, used internally
1.17 + ///\param PRIO Type of the priority of the items.
1.18 + ///\param IM A read and writable Item int map, used internally
1.19 ///to handle the cross references.
1.20 - ///\param _Compare A class for the ordering of the priorities. The
1.21 - ///default is \c std::less<_Prio>.
1.22 + ///\param CMP A class for the ordering of the priorities. The
1.23 + ///default is \c std::less<PRIO>.
1.24 ///
1.25 ///\sa BinHeap
1.26 ///\sa Dijkstra
1.27 #ifdef DOXYGEN
1.28 - template <typename _Prio,
1.29 - typename _ItemIntMap,
1.30 - typename _Compare>
1.31 + template <typename PRIO, typename IM, typename CMP>
1.32 #else
1.33 - template <typename _Prio,
1.34 - typename _ItemIntMap,
1.35 - typename _Compare = std::less<_Prio> >
1.36 + template <typename PRIO, typename IM, typename CMP = std::less<PRIO> >
1.37 #endif
1.38 class FibHeap {
1.39 public:
1.40 ///\e
1.41 - typedef _ItemIntMap ItemIntMap;
1.42 + typedef IM ItemIntMap;
1.43 ///\e
1.44 - typedef _Prio Prio;
1.45 + typedef PRIO Prio;
1.46 ///\e
1.47 typedef typename ItemIntMap::Key Item;
1.48 ///\e
1.49 typedef std::pair<Item,Prio> Pair;
1.50 ///\e
1.51 - typedef _Compare Compare;
1.52 + typedef CMP Compare;
1.53
1.54 private:
1.55 - class store;
1.56 + class Store;
1.57
1.58 - std::vector<store> container;
1.59 - int minimum;
1.60 - ItemIntMap &iimap;
1.61 - Compare comp;
1.62 - int num_items;
1.63 + std::vector<Store> _data;
1.64 + int _minimum;
1.65 + ItemIntMap &_iim;
1.66 + Compare _comp;
1.67 + int _num;
1.68
1.69 public:
1.70 - ///Status of the nodes
1.71 +
1.72 + /// \brief Type to represent the items states.
1.73 + ///
1.74 + /// Each Item element have a state associated to it. It may be "in heap",
1.75 + /// "pre heap" or "post heap". The latter two are indifferent from the
1.76 + /// heap's point of view, but may be useful to the user.
1.77 + ///
1.78 + /// The item-int map must be initialized in such way that it assigns
1.79 + /// \c PRE_HEAP (<tt>-1</tt>) to any element to be put in the heap.
1.80 enum State {
1.81 - ///The node is in the heap
1.82 - IN_HEAP = 0,
1.83 - ///The node has never been in the heap
1.84 - PRE_HEAP = -1,
1.85 - ///The node was in the heap but it got out of it
1.86 - POST_HEAP = -2
1.87 + IN_HEAP = 0, ///< = 0.
1.88 + PRE_HEAP = -1, ///< = -1.
1.89 + POST_HEAP = -2 ///< = -2.
1.90 };
1.91
1.92 /// \brief The constructor
1.93 ///
1.94 - /// \c _iimap should be given to the constructor, since it is
1.95 + /// \c map should be given to the constructor, since it is
1.96 /// used internally to handle the cross references.
1.97 - explicit FibHeap(ItemIntMap &_iimap)
1.98 - : minimum(0), iimap(_iimap), num_items() {}
1.99 + explicit FibHeap(ItemIntMap &map)
1.100 + : _minimum(0), _iim(map), _num() {}
1.101
1.102 /// \brief The constructor
1.103 ///
1.104 - /// \c _iimap should be given to the constructor, since it is used
1.105 - /// internally to handle the cross references. \c _comp is an
1.106 + /// \c map should be given to the constructor, since it is used
1.107 + /// internally to handle the cross references. \c comp is an
1.108 /// object for ordering of the priorities.
1.109 - FibHeap(ItemIntMap &_iimap, const Compare &_comp)
1.110 - : minimum(0), iimap(_iimap), comp(_comp), num_items() {}
1.111 + FibHeap(ItemIntMap &map, const Compare &comp)
1.112 + : _minimum(0), _iim(map), _comp(comp), _num() {}
1.113
1.114 /// \brief The number of items stored in the heap.
1.115 ///
1.116 /// Returns the number of items stored in the heap.
1.117 - int size() const { return num_items; }
1.118 + int size() const { return _num; }
1.119
1.120 /// \brief Checks if the heap stores no items.
1.121 ///
1.122 /// Returns \c true if and only if the heap stores no items.
1.123 - bool empty() const { return num_items==0; }
1.124 + bool empty() const { return _num==0; }
1.125
1.126 /// \brief Make empty this heap.
1.127 ///
1.128 @@ -125,7 +126,7 @@
1.129 /// should first clear the heap and after that you should set the
1.130 /// cross reference map for each item to \c PRE_HEAP.
1.131 void clear() {
1.132 - container.clear(); minimum = 0; num_items = 0;
1.133 + _data.clear(); _minimum = 0; _num = 0;
1.134 }
1.135
1.136 /// \brief \c item gets to the heap with priority \c value independently
1.137 @@ -135,10 +136,10 @@
1.138 /// stored in the heap and it calls \ref decrease(\c item, \c value) or
1.139 /// \ref increase(\c item, \c value) otherwise.
1.140 void set (const Item& item, const Prio& value) {
1.141 - int i=iimap[item];
1.142 - if ( i >= 0 && container[i].in ) {
1.143 - if ( comp(value, container[i].prio) ) decrease(item, value);
1.144 - if ( comp(container[i].prio, value) ) increase(item, value);
1.145 + int i=_iim[item];
1.146 + if ( i >= 0 && _data[i].in ) {
1.147 + if ( _comp(value, _data[i].prio) ) decrease(item, value);
1.148 + if ( _comp(_data[i].prio, value) ) increase(item, value);
1.149 } else push(item, value);
1.150 }
1.151
1.152 @@ -147,33 +148,33 @@
1.153 /// Adds \c item to the heap with priority \c value.
1.154 /// \pre \c item must not be stored in the heap.
1.155 void push (const Item& item, const Prio& value) {
1.156 - int i=iimap[item];
1.157 + int i=_iim[item];
1.158 if ( i < 0 ) {
1.159 - int s=container.size();
1.160 - iimap.set( item, s );
1.161 - store st;
1.162 + int s=_data.size();
1.163 + _iim.set( item, s );
1.164 + Store st;
1.165 st.name=item;
1.166 - container.push_back(st);
1.167 + _data.push_back(st);
1.168 i=s;
1.169 } else {
1.170 - container[i].parent=container[i].child=-1;
1.171 - container[i].degree=0;
1.172 - container[i].in=true;
1.173 - container[i].marked=false;
1.174 + _data[i].parent=_data[i].child=-1;
1.175 + _data[i].degree=0;
1.176 + _data[i].in=true;
1.177 + _data[i].marked=false;
1.178 }
1.179
1.180 - if ( num_items ) {
1.181 - container[container[minimum].right_neighbor].left_neighbor=i;
1.182 - container[i].right_neighbor=container[minimum].right_neighbor;
1.183 - container[minimum].right_neighbor=i;
1.184 - container[i].left_neighbor=minimum;
1.185 - if ( comp( value, container[minimum].prio) ) minimum=i;
1.186 + if ( _num ) {
1.187 + _data[_data[_minimum].right_neighbor].left_neighbor=i;
1.188 + _data[i].right_neighbor=_data[_minimum].right_neighbor;
1.189 + _data[_minimum].right_neighbor=i;
1.190 + _data[i].left_neighbor=_minimum;
1.191 + if ( _comp( value, _data[_minimum].prio) ) _minimum=i;
1.192 } else {
1.193 - container[i].right_neighbor=container[i].left_neighbor=i;
1.194 - minimum=i;
1.195 + _data[i].right_neighbor=_data[i].left_neighbor=i;
1.196 + _minimum=i;
1.197 }
1.198 - container[i].prio=value;
1.199 - ++num_items;
1.200 + _data[i].prio=value;
1.201 + ++_num;
1.202 }
1.203
1.204 /// \brief Returns the item with minimum priority relative to \c Compare.
1.205 @@ -181,20 +182,20 @@
1.206 /// This method returns the item with minimum priority relative to \c
1.207 /// Compare.
1.208 /// \pre The heap must be nonempty.
1.209 - Item top() const { return container[minimum].name; }
1.210 + Item top() const { return _data[_minimum].name; }
1.211
1.212 /// \brief Returns the minimum priority relative to \c Compare.
1.213 ///
1.214 /// It returns the minimum priority relative to \c Compare.
1.215 /// \pre The heap must be nonempty.
1.216 - const Prio& prio() const { return container[minimum].prio; }
1.217 + const Prio& prio() const { return _data[_minimum].prio; }
1.218
1.219 /// \brief Returns the priority of \c item.
1.220 ///
1.221 /// It returns the priority of \c item.
1.222 /// \pre \c item must be in the heap.
1.223 const Prio& operator[](const Item& item) const {
1.224 - return container[iimap[item]].prio;
1.225 + return _data[_iim[item]].prio;
1.226 }
1.227
1.228 /// \brief Deletes the item with minimum priority relative to \c Compare.
1.229 @@ -204,33 +205,33 @@
1.230 /// \pre The heap must be non-empty.
1.231 void pop() {
1.232 /*The first case is that there are only one root.*/
1.233 - if ( container[minimum].left_neighbor==minimum ) {
1.234 - container[minimum].in=false;
1.235 - if ( container[minimum].degree!=0 ) {
1.236 - makeroot(container[minimum].child);
1.237 - minimum=container[minimum].child;
1.238 + if ( _data[_minimum].left_neighbor==_minimum ) {
1.239 + _data[_minimum].in=false;
1.240 + if ( _data[_minimum].degree!=0 ) {
1.241 + makeroot(_data[_minimum].child);
1.242 + _minimum=_data[_minimum].child;
1.243 balance();
1.244 }
1.245 } else {
1.246 - int right=container[minimum].right_neighbor;
1.247 - unlace(minimum);
1.248 - container[minimum].in=false;
1.249 - if ( container[minimum].degree > 0 ) {
1.250 - int left=container[minimum].left_neighbor;
1.251 - int child=container[minimum].child;
1.252 - int last_child=container[child].left_neighbor;
1.253 + int right=_data[_minimum].right_neighbor;
1.254 + unlace(_minimum);
1.255 + _data[_minimum].in=false;
1.256 + if ( _data[_minimum].degree > 0 ) {
1.257 + int left=_data[_minimum].left_neighbor;
1.258 + int child=_data[_minimum].child;
1.259 + int last_child=_data[child].left_neighbor;
1.260
1.261 makeroot(child);
1.262
1.263 - container[left].right_neighbor=child;
1.264 - container[child].left_neighbor=left;
1.265 - container[right].left_neighbor=last_child;
1.266 - container[last_child].right_neighbor=right;
1.267 + _data[left].right_neighbor=child;
1.268 + _data[child].left_neighbor=left;
1.269 + _data[right].left_neighbor=last_child;
1.270 + _data[last_child].right_neighbor=right;
1.271 }
1.272 - minimum=right;
1.273 + _minimum=right;
1.274 balance();
1.275 } // the case where there are more roots
1.276 - --num_items;
1.277 + --_num;
1.278 }
1.279
1.280 /// \brief Deletes \c item from the heap.
1.281 @@ -238,15 +239,15 @@
1.282 /// This method deletes \c item from the heap, if \c item was already
1.283 /// stored in the heap. It is quite inefficient in Fibonacci heaps.
1.284 void erase (const Item& item) {
1.285 - int i=iimap[item];
1.286 + int i=_iim[item];
1.287
1.288 - if ( i >= 0 && container[i].in ) {
1.289 - if ( container[i].parent!=-1 ) {
1.290 - int p=container[i].parent;
1.291 + if ( i >= 0 && _data[i].in ) {
1.292 + if ( _data[i].parent!=-1 ) {
1.293 + int p=_data[i].parent;
1.294 cut(i,p);
1.295 cascade(p);
1.296 }
1.297 - minimum=i; //As if its prio would be -infinity
1.298 + _minimum=i; //As if its prio would be -infinity
1.299 pop();
1.300 }
1.301 }
1.302 @@ -257,15 +258,15 @@
1.303 /// \pre \c item must be stored in the heap with priority at least \c
1.304 /// value relative to \c Compare.
1.305 void decrease (Item item, const Prio& value) {
1.306 - int i=iimap[item];
1.307 - container[i].prio=value;
1.308 - int p=container[i].parent;
1.309 + int i=_iim[item];
1.310 + _data[i].prio=value;
1.311 + int p=_data[i].parent;
1.312
1.313 - if ( p!=-1 && comp(value, container[p].prio) ) {
1.314 + if ( p!=-1 && _comp(value, _data[p].prio) ) {
1.315 cut(i,p);
1.316 cascade(p);
1.317 }
1.318 - if ( comp(value, container[minimum].prio) ) minimum=i;
1.319 + if ( _comp(value, _data[_minimum].prio) ) _minimum=i;
1.320 }
1.321
1.322 /// \brief Increases the priority of \c item to \c value.
1.323 @@ -289,9 +290,9 @@
1.324 /// otherwise. In the latter case it is possible that \c item will
1.325 /// get back to the heap again.
1.326 State state(const Item &item) const {
1.327 - int i=iimap[item];
1.328 + int i=_iim[item];
1.329 if( i>=0 ) {
1.330 - if ( container[i].in ) i=0;
1.331 + if ( _data[i].in ) i=0;
1.332 else i=-2;
1.333 }
1.334 return State(i);
1.335 @@ -301,7 +302,7 @@
1.336 ///
1.337 /// Sets the state of the \c item in the heap. It can be used to
1.338 /// manually clear the heap when it is important to achive the
1.339 - /// better time complexity.
1.340 + /// better time _complexity.
1.341 /// \param i The item.
1.342 /// \param st The state. It should not be \c IN_HEAP.
1.343 void state(const Item& i, State st) {
1.344 @@ -311,7 +312,7 @@
1.345 if (state(i) == IN_HEAP) {
1.346 erase(i);
1.347 }
1.348 - iimap[i] = st;
1.349 + _iim[i] = st;
1.350 break;
1.351 case IN_HEAP:
1.352 break;
1.353 @@ -322,7 +323,7 @@
1.354
1.355 void balance() {
1.356
1.357 - int maxdeg=int( std::floor( 2.08*log(double(container.size()))))+1;
1.358 + int maxdeg=int( std::floor( 2.08*log(double(_data.size()))))+1;
1.359
1.360 std::vector<int> A(maxdeg,-1);
1.361
1.362 @@ -330,18 +331,18 @@
1.363 *Recall that now minimum does not point to the minimum prio element.
1.364 *We set minimum to this during balance().
1.365 */
1.366 - int anchor=container[minimum].left_neighbor;
1.367 - int next=minimum;
1.368 + int anchor=_data[_minimum].left_neighbor;
1.369 + int next=_minimum;
1.370 bool end=false;
1.371
1.372 do {
1.373 int active=next;
1.374 if ( anchor==active ) end=true;
1.375 - int d=container[active].degree;
1.376 - next=container[active].right_neighbor;
1.377 + int d=_data[active].degree;
1.378 + next=_data[active].right_neighbor;
1.379
1.380 while (A[d]!=-1) {
1.381 - if( comp(container[active].prio, container[A[d]].prio) ) {
1.382 + if( _comp(_data[active].prio, _data[A[d]].prio) ) {
1.383 fuse(active,A[d]);
1.384 } else {
1.385 fuse(A[d],active);
1.386 @@ -354,21 +355,21 @@
1.387 } while ( !end );
1.388
1.389
1.390 - while ( container[minimum].parent >=0 )
1.391 - minimum=container[minimum].parent;
1.392 - int s=minimum;
1.393 - int m=minimum;
1.394 + while ( _data[_minimum].parent >=0 )
1.395 + _minimum=_data[_minimum].parent;
1.396 + int s=_minimum;
1.397 + int m=_minimum;
1.398 do {
1.399 - if ( comp(container[s].prio, container[minimum].prio) ) minimum=s;
1.400 - s=container[s].right_neighbor;
1.401 + if ( _comp(_data[s].prio, _data[_minimum].prio) ) _minimum=s;
1.402 + s=_data[s].right_neighbor;
1.403 } while ( s != m );
1.404 }
1.405
1.406 void makeroot(int c) {
1.407 int s=c;
1.408 do {
1.409 - container[s].parent=-1;
1.410 - s=container[s].right_neighbor;
1.411 + _data[s].parent=-1;
1.412 + s=_data[s].right_neighbor;
1.413 } while ( s != c );
1.414 }
1.415
1.416 @@ -376,32 +377,32 @@
1.417 /*
1.418 *Replacing a from the children of b.
1.419 */
1.420 - --container[b].degree;
1.421 + --_data[b].degree;
1.422
1.423 - if ( container[b].degree !=0 ) {
1.424 - int child=container[b].child;
1.425 + if ( _data[b].degree !=0 ) {
1.426 + int child=_data[b].child;
1.427 if ( child==a )
1.428 - container[b].child=container[child].right_neighbor;
1.429 + _data[b].child=_data[child].right_neighbor;
1.430 unlace(a);
1.431 }
1.432
1.433
1.434 /*Lacing a to the roots.*/
1.435 - int right=container[minimum].right_neighbor;
1.436 - container[minimum].right_neighbor=a;
1.437 - container[a].left_neighbor=minimum;
1.438 - container[a].right_neighbor=right;
1.439 - container[right].left_neighbor=a;
1.440 + int right=_data[_minimum].right_neighbor;
1.441 + _data[_minimum].right_neighbor=a;
1.442 + _data[a].left_neighbor=_minimum;
1.443 + _data[a].right_neighbor=right;
1.444 + _data[right].left_neighbor=a;
1.445
1.446 - container[a].parent=-1;
1.447 - container[a].marked=false;
1.448 + _data[a].parent=-1;
1.449 + _data[a].marked=false;
1.450 }
1.451
1.452 void cascade(int a) {
1.453 - if ( container[a].parent!=-1 ) {
1.454 - int p=container[a].parent;
1.455 + if ( _data[a].parent!=-1 ) {
1.456 + int p=_data[a].parent;
1.457
1.458 - if ( container[a].marked==false ) container[a].marked=true;
1.459 + if ( _data[a].marked==false ) _data[a].marked=true;
1.460 else {
1.461 cut(a,p);
1.462 cascade(p);
1.463 @@ -413,38 +414,38 @@
1.464 unlace(b);
1.465
1.466 /*Lacing b under a.*/
1.467 - container[b].parent=a;
1.468 + _data[b].parent=a;
1.469
1.470 - if (container[a].degree==0) {
1.471 - container[b].left_neighbor=b;
1.472 - container[b].right_neighbor=b;
1.473 - container[a].child=b;
1.474 + if (_data[a].degree==0) {
1.475 + _data[b].left_neighbor=b;
1.476 + _data[b].right_neighbor=b;
1.477 + _data[a].child=b;
1.478 } else {
1.479 - int child=container[a].child;
1.480 - int last_child=container[child].left_neighbor;
1.481 - container[child].left_neighbor=b;
1.482 - container[b].right_neighbor=child;
1.483 - container[last_child].right_neighbor=b;
1.484 - container[b].left_neighbor=last_child;
1.485 + int child=_data[a].child;
1.486 + int last_child=_data[child].left_neighbor;
1.487 + _data[child].left_neighbor=b;
1.488 + _data[b].right_neighbor=child;
1.489 + _data[last_child].right_neighbor=b;
1.490 + _data[b].left_neighbor=last_child;
1.491 }
1.492
1.493 - ++container[a].degree;
1.494 + ++_data[a].degree;
1.495
1.496 - container[b].marked=false;
1.497 + _data[b].marked=false;
1.498 }
1.499
1.500 /*
1.501 *It is invoked only if a has siblings.
1.502 */
1.503 void unlace(int a) {
1.504 - int leftn=container[a].left_neighbor;
1.505 - int rightn=container[a].right_neighbor;
1.506 - container[leftn].right_neighbor=rightn;
1.507 - container[rightn].left_neighbor=leftn;
1.508 + int leftn=_data[a].left_neighbor;
1.509 + int rightn=_data[a].right_neighbor;
1.510 + _data[leftn].right_neighbor=rightn;
1.511 + _data[rightn].left_neighbor=leftn;
1.512 }
1.513
1.514
1.515 - class store {
1.516 + class Store {
1.517 friend class FibHeap;
1.518
1.519 Item name;
1.520 @@ -457,7 +458,7 @@
1.521 bool in;
1.522 Prio prio;
1.523
1.524 - store() : parent(-1), child(-1), degree(), marked(false), in(true) {}
1.525 + Store() : parent(-1), child(-1), degree(), marked(false), in(true) {}
1.526 };
1.527 };
1.528