lemon/bucket_heap.h
changeset 2256 b22dfb6c5ff3
parent 2089 fce8db723736
child 2263 9273fe7d850c
equal deleted inserted replaced
3:daf5a635951a 4:b2fc6c2fcb72
   600     /// \param p The priority of the item.
   600     /// \param p The priority of the item.
   601     void push(const Item &i, const Prio &p) {
   601     void push(const Item &i, const Prio &p) {
   602       int idx;
   602       int idx;
   603       if (free == -1) {
   603       if (free == -1) {
   604         idx = data.size();
   604         idx = data.size();
   605         data.push_back(BucketItem(i, p));
   605         data.push_back(BucketItem(i));
   606       } else {
   606       } else {
   607         idx = free;
   607         idx = free;
   608         free = data[idx].next;
   608         free = data[idx].next;
   609         data[idx].item = i; data[idx].value = p;
   609         data[idx].item = i;
   610       }
   610       }
   611       index[i] = idx;
   611       index[i] = idx;
   612       if (p >= (int)first.size()) first.resize(p + 1, -1);
   612       if (p >= (int)first.size()) first.resize(p + 1, -1);
   613       data[idx].next = first[p];
   613       data[idx].next = first[p];
   614       first[p] = idx;
   614       first[p] = idx;
   656       --num;
   656       --num;
   657     }
   657     }
   658     
   658     
   659     /// \brief Returns the priority of \c i.
   659     /// \brief Returns the priority of \c i.
   660     ///
   660     ///
   661     /// This function returns the priority of item \c i.  
   661     /// This function returns the priority of item \c i.
       
   662     /// \warning This operator is not a constant time function
       
   663     /// because it scans the whole data structure to find the proper
       
   664     /// value.  
   662     /// \pre \c i must be in the heap.
   665     /// \pre \c i must be in the heap.
   663     /// \param i The item.
   666     /// \param i The item.
   664     Prio operator[](const Item &i) const {
   667     Prio operator[](const Item &i) const {
   665       int idx = index[i];
   668       for (int k = 0; k < first.size(); ++k) {
   666       return data[idx].value;
   669         int idx = first[k];
       
   670         while (idx != -1) {
       
   671           if (data[idx].item == i) {
       
   672             return k;
       
   673           }
       
   674           idx = data[idx].next;
       
   675         }
       
   676       }
       
   677       return -1;
   667     }
   678     }
   668 
   679 
   669     /// \brief Returns if \c item is in, has already been in, or has 
   680     /// \brief Returns if \c item is in, has already been in, or has 
   670     /// never been in the heap.
   681     /// never been in the heap.
   671     ///
   682     ///
   681     }
   692     }
   682 
   693 
   683   private:
   694   private:
   684 
   695 
   685     struct BucketItem {
   696     struct BucketItem {
   686       BucketItem(const Item& _item, int _value) 
   697       BucketItem(const Item& _item) 
   687 	: item(_item), value(_value) {}
   698 	: item(_item) {}
   688 
   699 
   689       Item item;
   700       Item item;
   690       int value;
       
   691 
       
   692       int next;
   701       int next;
   693     };
   702     };
   694 
   703 
   695     ItemIntMap& index;
   704     ItemIntMap& index;
   696     std::vector<int> first;
   705     std::vector<int> first;
   734 
   743 
   735     void push(const Item &i, const Prio &p) {
   744     void push(const Item &i, const Prio &p) {
   736       int idx;
   745       int idx;
   737       if (free == -1) {
   746       if (free == -1) {
   738         idx = data.size();
   747         idx = data.size();
   739         data.push_back(BucketItem(i, p));
   748         data.push_back(BucketItem(i));
   740       } else {
   749       } else {
   741         idx = free;
   750         idx = free;
   742         free = data[idx].next;
   751         free = data[idx].next;
   743         data[idx].item = i; data[idx].value = p;
   752         data[idx].item = i;
   744       }
   753       }
   745       index[i] = idx;
   754       index[i] = idx;
   746       if (p >= (int)first.size()) first.resize(p + 1, -1);
   755       if (p >= (int)first.size()) first.resize(p + 1, -1);
   747       data[idx].next = first[p];
   756       data[idx].next = first[p];
   748       first[p] = idx;
   757       first[p] = idx;
   777       free = idx;
   786       free = idx;
   778       --num;
   787       --num;
   779     }
   788     }
   780     
   789     
   781     Prio operator[](const Item &i) const {
   790     Prio operator[](const Item &i) const {
   782       int idx = index[i];
   791       for (int k = 0; k < first.size(); ++k) {
   783       return data[idx].value;
   792         int idx = first[k];
       
   793         while (idx != -1) {
       
   794           if (data[idx].item == i) {
       
   795             return k;
       
   796           }
       
   797           idx = data[idx].next;
       
   798         }
       
   799       }
       
   800       return -1;
   784     }
   801     }
   785 
   802 
   786     state_enum state(const Item &i) const {
   803     state_enum state(const Item &i) const {
   787       int idx = index[i];
   804       int idx = index[i];
   788       if (idx >= 0) idx = 0;
   805       if (idx >= 0) idx = 0;
   790     }
   807     }
   791 
   808 
   792   private:
   809   private:
   793 
   810 
   794     struct BucketItem {
   811     struct BucketItem {
   795       BucketItem(const Item& _item, int _value) 
   812       BucketItem(const Item& _item) : item(_item) {}
   796 	: item(_item), value(_value) {}
       
   797 
   813 
   798       Item item;
   814       Item item;
   799       int value;
       
   800 
   815 
   801       int next;
   816       int next;
   802     };
   817     };
   803 
   818 
   804     ItemIntMap& index;
   819     ItemIntMap& index;