diff -r d8475431bbbb -r 8e85e6bbefdf lemon/bin_heap.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lemon/bin_heap.h	Mon May 23 04:48:14 2005 +0000
@@ -0,0 +1,303 @@
+/* -*- C++ -*-
+ * lemon/bin_heap.h - Part of LEMON, a generic C++ optimization library
+ *
+ * Copyright (C) 2005 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
+ * (Egervary Research Group on Combinatorial Optimization, EGRES).
+ *
+ * Permission to use, modify and distribute this software is granted
+ * provided that this copyright notice appears in all copies. For
+ * precise terms see the accompanying LICENSE file.
+ *
+ * This software is provided "AS IS" with no warranty of any kind,
+ * express or implied, and with no claim as to its suitability for any
+ * purpose.
+ *
+ */
+
+#ifndef LEMON_BIN_HEAP_H
+#define LEMON_BIN_HEAP_H
+
+///\ingroup auxdat
+///\file
+///\brief Binary Heap implementation.
+
+#include <vector>
+#include <utility>
+#include <functional>
+
+namespace lemon {
+
+  /// \addtogroup auxdat
+  /// @{
+
+  /// A Binary Heap implementation.
+  
+  ///This class implements the \e binary \e heap data structure. A \e heap
+  ///is a data structure for storing items with specified values called \e
+  ///priorities in such a way that finding the item with minimum priority is
+  ///efficient. \c Compare specifies the ordering of the priorities. In a heap
+  ///one can change the priority of an item, add or erase an item, etc.
+  ///
+  ///\param Item Type of the items to be stored.  
+  ///\param Prio Type of the priority of the items.
+  ///\param ItemIntMap A read and writable Item int map, used internally
+  ///to handle the cross references.
+  ///\param Compare A class for the ordering of the priorities. The
+  ///default is \c std::less<Prio>.
+  ///
+  ///\sa FibHeap
+  ///\sa Dijkstra
+  template <typename Item, typename Prio, typename ItemIntMap,
+	    typename Compare = std::less<Prio> >
+  class BinHeap {
+
+  public:
+    typedef Item                             ItemType;
+    // FIXME: stl-ben nem ezt hivjak value_type -nak, hanem a kovetkezot...
+    typedef Prio                             PrioType;
+    typedef std::pair<ItemType,PrioType>     PairType;
+    typedef ItemIntMap                       ItemIntMapType;
+    typedef Compare                          PrioCompare;
+
+    /// \brief Type to represent the items states.
+    ///
+    /// Each Item element have a state associated to it. It may be "in heap",
+    /// "pre heap" or "post heap". The latter two are indifferent from the
+    /// heap's point of view, but may be useful to the user.
+    ///
+    /// The ItemIntMap \e should be initialized in such way that it maps
+    /// PRE_HEAP (-1) to any element to be put in the heap...
+    enum state_enum {
+      IN_HEAP = 0,
+      PRE_HEAP = -1,
+      POST_HEAP = -2
+    };
+
+  private:
+    std::vector<PairType> data;
+    Compare comp;
+    ItemIntMap &iim;
+
+  public:
+    /// \brief The constructor.
+    ///
+    /// The constructor.
+    /// \param _iim should be given to the constructor, since it is used
+    /// internally to handle the cross references. The value of the map
+    /// should be PRE_HEAP (-1) for each element.
+    explicit BinHeap(ItemIntMap &_iim) : iim(_iim) {}
+    
+    /// \brief The constructor.
+    ///
+    /// The constructor.
+    /// \param _iim should be given to the constructor, since it is used
+    /// internally to handle the cross references. The value of the map
+    /// should be PRE_HEAP (-1) for each element.
+    ///
+    /// \param _comp The comparator function object.
+    BinHeap(ItemIntMap &_iim, const Compare &_comp) 
+      : iim(_iim), comp(_comp) {}
+
+
+    /// The number of items stored in the heap.
+    ///
+    /// \brief Returns the number of items stored in the heap.
+    int size() const { return data.size(); }
+    
+    /// \brief Checks if the heap stores no items.
+    ///
+    /// Returns \c true if and only if the heap stores no items.
+    bool empty() const { return data.empty(); }
+
+  private:
+    static int parent(int i) { return (i-1)/2; }
+    static int second_child(int i) { return 2*i+2; }
+    bool less(const PairType &p1, const PairType &p2) const {
+      return comp(p1.second, p2.second);
+    }
+
+    int bubble_up(int hole, PairType p);
+    int bubble_down(int hole, PairType p, int length);
+
+    void move(const PairType &p, int i) {
+      data[i] = p;
+      iim.set(p.first, i);
+    }
+
+    void rmidx(int h) {
+      int n = data.size()-1;
+      if( h>=0 && h<=n ) {
+	iim.set(data[h].first, POST_HEAP);
+	if ( h<n ) {
+	  bubble_down(h, data[n], n);
+	}
+	data.pop_back();
+      }
+    }
+
+  public:
+    /// \brief Insert a pair of item and priority into the heap.
+    ///
+    /// Adds \c p.first to the heap with priority \c p.second.
+    /// \param p The pair to insert.
+    void push(const PairType &p) {
+      int n = data.size();
+      data.resize(n+1);
+      bubble_up(n, p);
+    }
+
+    /// \brief Insert an item into the heap with the given heap.
+    ///    
+    /// Adds \c i to the heap with priority \c p. 
+    /// \param i The item to insert.
+    /// \param p The priority of the item.
+    void push(const Item &i, const Prio &p) { push(PairType(i,p)); }
+
+    /// \brief Returns the item with minimum priority relative to \c Compare.
+    ///
+    /// This method returns the item with minimum priority relative to \c
+    /// Compare.  
+    /// \pre The heap must be nonempty.  
+    Item top() const {
+      return data[0].first;
+    }
+
+    /// \brief Returns the minimum priority relative to \c Compare.
+    ///
+    /// It returns the minimum priority relative to \c Compare.
+    /// \pre The heap must be nonempty.
+    Prio prio() const {
+      return data[0].second;
+    }
+
+    /// \brief Deletes the item with minimum priority relative to \c Compare.
+    ///
+    /// This method deletes the item with minimum priority relative to \c
+    /// Compare from the heap.  
+    /// \pre The heap must be non-empty.  
+    void pop() {
+      rmidx(0);
+    }
+
+    /// \brief Deletes \c i from the heap.
+    ///
+    /// This method deletes item \c i from the heap, if \c i was
+    /// already stored in the heap.
+    /// \param i The item to erase. 
+    void erase(const Item &i) {
+      rmidx(iim[i]);
+    }
+
+    
+    /// \brief Returns the priority of \c i.
+    ///
+    /// This function returns the priority of item \c i.  
+    /// \pre \c i must be in the heap.
+    /// \param i The item.
+    Prio operator[](const Item &i) const {
+      int idx = iim[i];
+      return data[idx].second;
+    }
+
+    /// \brief \c i gets to the heap with priority \c p independently 
+    /// if \c i was already there.
+    ///
+    /// This method calls \ref push(\c i, \c p) if \c i is not stored
+    /// in the heap and sets the priority of \c i to \c p otherwise.
+    /// \param i The item.
+    /// \param p The priority.
+    void set(const Item &i, const Prio &p) {
+      int idx = iim[i];
+      if( idx < 0 ) {
+	push(i,p);
+      }
+      else if( comp(p, data[idx].second) ) {
+	bubble_up(idx, PairType(i,p));
+      }
+      else {
+	bubble_down(idx, PairType(i,p), data.size());
+      }
+    }
+
+    /// \brief Decreases the priority of \c i to \c p.
+
+    /// This method decreases the priority of item \c i to \c p.
+    /// \pre \c i must be stored in the heap with priority at least \c
+    /// p relative to \c Compare.
+    /// \param i The item.
+    /// \param p The priority.
+    void decrease(const Item &i, const Prio &p) {
+      int idx = iim[i];
+      bubble_up(idx, PairType(i,p));
+    }
+    
+    /// \brief Increases the priority of \c i to \c p.
+    ///
+    /// This method sets the priority of item \c i to \c p. 
+    /// \pre \c i must be stored in the heap with priority at most \c
+    /// p relative to \c Compare.
+    /// \param i The item.
+    /// \param p The priority.
+    void increase(const Item &i, const Prio &p) {
+      int idx = iim[i];
+      bubble_down(idx, PairType(i,p), data.size());
+    }
+
+    /// \brief Returns if \c item is in, has already been in, or has 
+    /// never been in the heap.
+    ///
+    /// This method returns PRE_HEAP if \c item has never been in the
+    /// heap, IN_HEAP if it is in the heap at the moment, and POST_HEAP
+    /// otherwise. In the latter case it is possible that \c item will
+    /// get back to the heap again.
+    /// \param i The item.
+    state_enum state(const Item &i) const {
+      int s = iim[i];
+      if( s>=0 )
+	s=0;
+      return state_enum(s);
+    }
+
+  }; // class BinHeap
+
+  
+  template <typename K, typename V, typename M, typename C>
+  int BinHeap<K,V,M,C>::bubble_up(int hole, PairType p) {
+    int par = parent(hole);
+    while( hole>0 && less(p,data[par]) ) {
+      move(data[par],hole);
+      hole = par;
+      par = parent(hole);
+    }
+    move(p, hole);
+    return hole;
+  }
+
+  template <typename K, typename V, typename M, typename C>
+  int BinHeap<K,V,M,C>::bubble_down(int hole, PairType p, int length) {
+    int child = second_child(hole);
+    while(child < length) {
+      if( less(data[child-1], data[child]) ) {
+	--child;
+      }
+      if( !less(data[child], p) )
+	goto ok;
+      move(data[child], hole);
+      hole = child;
+      child = second_child(hole);
+    }
+    child--;
+    if( child<length && less(data[child], p) ) {
+      move(data[child], hole);
+      hole=child;
+    }
+  ok:
+    move(p, hole);
+    return hole;
+  }
+
+  ///@}
+
+} // namespace lemon
+
+#endif // LEMON_BIN_HEAP_H