lemon/fib_heap.h
changeset 1720 578d8b2b76c6
parent 1435 8e85e6bbefdf
child 1753 98d83dd56c1d
equal deleted inserted replaced
0:f0e658728745 1:784758e951c0
    86       PRE_HEAP = -1,
    86       PRE_HEAP = -1,
    87       ///The node was in the heap but it got out of it
    87       ///The node was in the heap but it got out of it
    88       POST_HEAP = -2
    88       POST_HEAP = -2
    89     };
    89     };
    90     
    90     
    91     ///The constructor
    91     /// \brief The constructor
    92 
    92     ///
    93     /**
    93     /// \c _iimap should be given to the constructor, since it is
    94        \c _iimap should be given to the constructor, since it is
    94     ///   used internally to handle the cross references.
    95        used internally to handle the cross references.
       
    96     */
       
    97     explicit FibHeap(ItemIntMap &_iimap) 
    95     explicit FibHeap(ItemIntMap &_iimap) 
    98       : minimum(0), iimap(_iimap), num_items() {} 
    96       : minimum(0), iimap(_iimap), num_items() {} 
    99  
    97  
   100     ///The constructor
    98     /// \brief The constructor
   101 
    99     ///
   102     /**
   100     /// \c _iimap should be given to the constructor, since it is used
   103        \c _iimap should be given to the constructor, since it is used
   101     /// internally to handle the cross references. \c _comp is an
   104        internally to handle the cross references. \c _comp is an
   102     /// object for ordering of the priorities. 
   105        object for ordering of the priorities. 
       
   106     */
       
   107     FibHeap(ItemIntMap &_iimap, const Compare &_comp) : minimum(0), 
   103     FibHeap(ItemIntMap &_iimap, const Compare &_comp) : minimum(0), 
   108 		  iimap(_iimap), comp(_comp), num_items() {}
   104 		  iimap(_iimap), comp(_comp), num_items() {}
   109     
   105     
   110     ///The number of items stored in the heap.
   106     /// \brief The number of items stored in the heap.
   111 
   107     ///
   112     /**
   108     /// Returns the number of items stored in the heap.
   113        Returns the number of items stored in the heap.
       
   114     */
       
   115     int size() const { return num_items; }
   109     int size() const { return num_items; }
   116 
   110 
   117     ///Checks if the heap stores no items.
   111     /// \brief Checks if the heap stores no items.
   118     
   112     ///
   119     /**
   113     ///   Returns \c true if and only if the heap stores no items.
   120        Returns \c true if and only if the heap stores no items.
       
   121     */
       
   122     bool empty() const { return num_items==0; }
   114     bool empty() const { return num_items==0; }
   123 
   115 
   124     ///\c item gets to the heap with priority \c value independently if \c item was already there.
   116     /// \brief Make empty this heap.
   125 
   117     /// 
   126     /**
   118     /// Make empty this heap.
   127        This method calls \ref push(\c item, \c value) if \c item is not
   119     void clear() { 
   128        stored in the heap and it calls \ref decrease(\c item, \c value) or
   120       for (int i = 0; i < (int)container.size(); ++i) {
   129        \ref increase(\c item, \c value) otherwise.
   121 	iimap[container[i].name] = -2;
   130     */
   122       }
       
   123       container.clear(); minimum = 0; num_items = 0;
       
   124     }
       
   125 
       
   126     /// \brief \c item gets to the heap with priority \c value independently 
       
   127     /// if \c item was already there.
       
   128     ///
       
   129     /// This method calls \ref push(\c item, \c value) if \c item is not
       
   130     /// stored in the heap and it calls \ref decrease(\c item, \c value) or
       
   131     /// \ref increase(\c item, \c value) otherwise.
   131     void set (Item const item, PrioType const value); 
   132     void set (Item const item, PrioType const value); 
   132     
   133     
   133     ///Adds \c item to the heap with priority \c value. 
   134     /// \brief Adds \c item to the heap with priority \c value. 
   134     
   135     ///    
   135     /**
   136     /// Adds \c item to the heap with priority \c value. 
   136        Adds \c item to the heap with priority \c value. 
   137     /// \pre \c item must not be stored in the heap. 
   137        \pre \c item must not be stored in the heap. 
       
   138     */
       
   139     void push (Item const item, PrioType const value);
   138     void push (Item const item, PrioType const value);
   140     
   139     
   141     ///Returns the item with minimum priority relative to \c Compare.
   140     /// \brief Returns the item with minimum priority relative to \c Compare.
   142     
   141     ///
   143     /**
   142     /// This method returns the item with minimum priority relative to \c
   144        This method returns the item with minimum priority relative to \c
   143     /// Compare.  
   145        Compare.  
   144     /// \pre The heap must be nonempty.  
   146        \pre The heap must be nonempty.  
       
   147     */
       
   148     Item top() const { return container[minimum].name; }
   145     Item top() const { return container[minimum].name; }
   149 
   146 
   150     ///Returns the minimum priority relative to \c Compare.
   147     /// \brief Returns the minimum priority relative to \c Compare.
   151 
   148     ///
   152     /**
   149     /// It returns the minimum priority relative to \c Compare.
   153        It returns the minimum priority relative to \c Compare.
   150     /// \pre The heap must be nonempty.
   154        \pre The heap must be nonempty.
       
   155     */
       
   156     PrioType prio() const { return container[minimum].prio; }
   151     PrioType prio() const { return container[minimum].prio; }
   157     
   152     
   158     ///Returns the priority of \c item.
   153     /// \brief Returns the priority of \c item.
   159 
   154     ///
   160     /**
   155     /// This function returns the priority of \c item.
   161        This function returns the priority of \c item.
   156     /// \pre \c item must be in the heap.
   162        \pre \c item must be in the heap.
       
   163     */
       
   164     PrioType& operator[](const Item& item) { 
   157     PrioType& operator[](const Item& item) { 
   165       return container[iimap[item]].prio; 
   158       return container[iimap[item]].prio; 
   166     }
   159     }
   167     
   160     
   168     ///Returns the priority of \c item.
   161     /// \brief Returns the priority of \c item.
   169     
   162     ///
   170     /**
   163     /// It returns the priority of \c item.
   171        It returns the priority of \c item.
   164     /// \pre \c item must be in the heap.
   172        \pre \c item must be in the heap.
       
   173     */
       
   174     const PrioType& operator[](const Item& item) const { 
   165     const PrioType& operator[](const Item& item) const { 
   175       return container[iimap[item]].prio; 
   166       return container[iimap[item]].prio; 
   176     }
   167     }
   177 
   168 
   178 
   169 
   179     ///Deletes the item with minimum priority relative to \c Compare.
   170     /// \brief Deletes the item with minimum priority relative to \c Compare.
   180 
   171     ///
   181     /**
   172     /// This method deletes the item with minimum priority relative to \c
   182     This method deletes the item with minimum priority relative to \c
   173     /// Compare from the heap.  
   183     Compare from the heap.  
   174     /// \pre The heap must be non-empty.  
   184     \pre The heap must be non-empty.  
       
   185     */
       
   186     void pop();
   175     void pop();
   187 
   176 
   188     ///Deletes \c item from the heap.
   177     /// \brief Deletes \c item from the heap.
   189 
   178     ///
   190     /**
   179     /// This method deletes \c item from the heap, if \c item was already
   191        This method deletes \c item from the heap, if \c item was already
   180     /// stored in the heap. It is quite inefficient in Fibonacci heaps.
   192        stored in the heap. It is quite inefficient in Fibonacci heaps.
       
   193     */
       
   194     void erase (const Item& item); 
   181     void erase (const Item& item); 
   195 
   182 
   196     ///Decreases the priority of \c item to \c value.
   183     /// \brief Decreases the priority of \c item to \c value.
   197 
   184     ///
   198     /**
   185     /// This method decreases the priority of \c item to \c value.
   199        This method decreases the priority of \c item to \c value.
   186     /// \pre \c item must be stored in the heap with priority at least \c
   200        \pre \c item must be stored in the heap with priority at least \c
   187     ///   value relative to \c Compare.
   201        value relative to \c Compare.
       
   202     */
       
   203     void decrease (Item item, PrioType const value); 
   188     void decrease (Item item, PrioType const value); 
   204 
   189 
   205     ///Increases the priority of \c item to \c value.
   190     /// \brief Increases the priority of \c item to \c value.
   206 
   191     ///
   207     /**
   192     /// This method sets the priority of \c item to \c value. Though
   208        This method sets the priority of \c item to \c value. Though
   193     /// there is no precondition on the priority of \c item, this
   209        there is no precondition on the priority of \c item, this
   194     /// method should be used only if it is indeed necessary to increase
   210        method should be used only if it is indeed necessary to increase
   195     /// (relative to \c Compare) the priority of \c item, because this
   211        (relative to \c Compare) the priority of \c item, because this
   196     /// method is inefficient.
   212        method is inefficient.
       
   213     */
       
   214     void increase (Item item, PrioType const value) {
   197     void increase (Item item, PrioType const value) {
   215       erase(item);
   198       erase(item);
   216       push(item, value);
   199       push(item, value);
   217     }
   200     }
   218 
   201 
   219 
   202 
   220     ///Returns if \c item is in, has already been in, or has never been in the heap.
   203     /// \brief Returns if \c item is in, has already been in, or has never 
   221 
   204     /// been in the heap.
   222     /**
   205     ///
   223        This method returns PRE_HEAP if \c item has never been in the
   206     /// This method returns PRE_HEAP if \c item has never been in the
   224        heap, IN_HEAP if it is in the heap at the moment, and POST_HEAP
   207     /// heap, IN_HEAP if it is in the heap at the moment, and POST_HEAP
   225        otherwise. In the latter case it is possible that \c item will
   208     /// otherwise. In the latter case it is possible that \c item will
   226        get back to the heap again.
   209     /// get back to the heap again.
   227     */
       
   228     state_enum state(const Item &item) const {
   210     state_enum state(const Item &item) const {
   229       int i=iimap[item];
   211       int i=iimap[item];
   230       if( i>=0 ) {
   212       if( i>=0 ) {
   231 	if ( container[i].in ) i=0;
   213 	if ( container[i].in ) i=0;
   232 	else i=-2; 
   214 	else i=-2;