LEMON/LEMON-main Changeset - r709:0747f332c478

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Changeset - r709:0747f332c478

« 683:9f529a

710:f1fe0d »

r709:0747f332c478

Wed, 08 Jul 2009 17:21:30

[Not Reviewed]

0 comments (0 inline)

kpeter (Peter Kovacs)
kpeter@inf.elte.hu

Improve and unify the documentation of heaps (#299) and avoid a warning in SimpleBucketHeap::operator[].

0 5 0

default

5 files changed with 563 insertions and 502 deletions:

lemon/bin_heap.h

lemon/bucket_heap.h

160

133

lemon/concepts/heap.h

lemon/fib_heap.h

120

113

lemon/radix_heap.h

111

106

↑ Collapse diff ↑

lemon/bin_heap.h

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 		/* -*- mode: C++; indent-tabs-mode: nil; -*-
+		 *
 		 * This file is a part of LEMON, a generic C++ optimization library.
+		 *
 		 * Copyright (C) 2003-2009
 		 * 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.
+		///\brief Binary heap implementation.
 		#include <vector>
 		#include <utility>
 		#include <functional>
 		namespace lemon {
 		  ///\ingroup auxdat
+		  /// \ingroup auxdat
 		  ///
-		  ///\brief A Binary Heap implementation.
+		  /// \brief Binary heap data structure.
 		  ///
 		  ///This class implements the \e binary \e heap data structure.
+		  /// This class implements the \e binary \e heap data structure.
 		  /// It fully conforms to the \ref concepts::Heap "heap concept".
 		  ///
 		  ///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 CMP specifies the ordering of the priorities.
 		  ///In a heap one can change the priority of an item, add or erase an
 		  ///item, etc.
 		  ///
 		  ///\tparam PR Type of the priority of the items.
 		  ///\tparam IM A read and writable item map with int values, used internally
 		  ///to handle the cross references.
 		  ///\tparam CMP A functor class for the ordering of the priorities.
 		  ///The default is \c std::less<PR>.
 		  ///
 		  ///\sa FibHeap
 		  ///\sa Dijkstra
 		  /// \tparam PR Type of the priorities of the items.
 		  /// \tparam IM A read-writable item map with \c int values, used
 		  /// internally to handle the cross references.
 		  /// \tparam CMP A functor class for comparing the priorities.
 		  /// The default is \c std::less<PR>.
 		#ifdef DOXYGEN
 		  template <typename PR, typename IM, typename CMP>
 		#else
 		  template <typename PR, typename IM, typename CMP = std::less<PR> >
 		#endif
 		  class BinHeap {
 		  public:
 		  public:
 		    ///\e
 		    /// Type of the item-int map.
 		    typedef IM ItemIntMap;
-		    ///\e
+		    /// Type of the priorities.
 		    typedef PR Prio;
-		    ///\e
+		    /// Type of the items stored in the heap.
 		    typedef typename ItemIntMap::Key Item;
-		    ///\e
+		    /// Type of the item-priority pairs.
 		    typedef std::pair<Item,Prio> Pair;
-		    ///\e
+		    /// Functor type for comparing the priorities.
 		    typedef CMP Compare;
-		    /// \brief Type to represent the items states.
+		    /// \brief Type to represent the states of the items.
 		    ///
 		    /// 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
 		    /// Each item has a state associated to it. It can 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 item-int map must be initialized in such way that it assigns
 		    /// \c PRE_HEAP (<tt>-1</tt>) to any element to be put in the heap.
 		    enum State {
 		      IN_HEAP = 0,    ///< = 0.
 		      PRE_HEAP = -1,  ///< = -1.
 		      POST_HEAP = -2  ///< = -2.
 		    };
 		  private:
 		    std::vector<Pair> _data;
 		    Compare _comp;
 		    ItemIntMap &_iim;
 		  public:
-		    /// \brief The constructor.
 		    /// \brief Constructor.
 		    ///
 		    /// The constructor.
 		    /// \param map should be given to the constructor, since it is used
 		    /// internally to handle the cross references. The value of the map
 		    /// must be \c PRE_HEAP (<tt>-1</tt>) for every item.
 		    /// Constructor.
 		    /// \param map A map that assigns \c int values to the items.
 		    /// It is used internally to handle the cross references.
 		    /// The assigned value must be \c PRE_HEAP (<tt>-1</tt>) for each item.
 		    explicit BinHeap(ItemIntMap &map) : _iim(map) {}
-		    /// \brief The constructor.
+		    /// \brief Constructor.
 		    ///
 		    /// The constructor.
 		    /// \param map 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.
 		    /// Constructor.
 		    /// \param map A map that assigns \c int values to the items.
 		    /// It is used internally to handle the cross references.
 		    /// The assigned value must be \c PRE_HEAP (<tt>-1</tt>) for each item.
 		    /// \param comp The function object used for comparing the priorities.
 		    BinHeap(ItemIntMap &map, const Compare &comp)
 		      : _iim(map), _comp(comp) {}
 		    /// The number of items stored in the heap.
+		    /// \brief The number of items stored in the heap.
 		    ///
-		    /// \brief Returns the number of items stored in the heap.
+		    /// This function returns the number of items stored in the heap.
 		    int size() const { return _data.size(); }
-		    /// \brief Checks if the heap stores no items.
+		    /// \brief Check if the heap is empty.
 		    ///
-		    /// Returns \c true if and only if the heap stores no items.
+		    /// This function returns \c true if the heap is empty.
 		    bool empty() const { return _data.empty(); }
-		    /// \brief Make empty this heap.
+		    /// \brief Make the heap empty.
 		    ///
 		    /// Make empty this heap. It does not change the cross reference map.
 		    /// If you want to reuse what is not surely empty you should first clear
 		    /// the heap and after that you should set the cross reference map for
 		    /// each item to \c PRE_HEAP.
 		    /// This functon makes the heap empty.
 		    /// It does not change the cross reference map. If you want to reuse
 		    /// a heap that is not surely empty, you should first clear it and
 		    /// then you should set the cross reference map to \c PRE_HEAP
 		    /// for each item.
 		    void clear() {
 		      _data.clear();
+		    }
 		  private:
 		    static int parent(int i) { return (i-1)/2; }
 		    static int second_child(int i) { return 2*i+2; }
 		    bool less(const Pair &p1, const Pair &p2) const {
 		      return _comp(p1.second, p2.second);
+		    }
 		    int bubble_up(int hole, Pair 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;
+		    }
 		    int bubble_down(int hole, Pair 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;
+		    }
 		    void move(const Pair &p, int i) {
 		      _data[i] = p;
 		      _iim.set(p.first, i);
+		    }
 		  public:
 		    /// \brief Insert a pair of item and priority into the heap.
 		    ///
-		    /// Adds \c p.first to the heap with priority \c p.second.
+		    /// This function inserts \c p.first to the heap with priority
 		    /// \c p.second.
 		    /// \param p The pair to insert.
 		    /// \pre \c p.first must not be stored in the heap.
 		    void push(const Pair &p) {
 		      int n = _data.size();
 		      _data.resize(n+1);
 		      bubble_up(n, p);
+		    }
-		    /// \brief Insert an item into the heap with the given heap.
+		    /// \brief Insert an item into the heap with the given priority.
 		    ///
-		    /// Adds \c i to the heap with priority \c p.
+		    /// This function inserts the given item into the heap with the
 		    /// given priority.
 		    /// \param i The item to insert.
 		    /// \param p The priority of the item.
 		    /// \pre \e i must not be stored in the heap.
 		    void push(const Item &i, const Prio &p) { push(Pair(i,p)); }
-		    /// \brief Returns the item with minimum priority relative to \c Compare.
+		    /// \brief Return the item having minimum priority.
 		    ///
 		    /// This method returns the item with minimum priority relative to \c
 		    /// Compare.
-		    /// \pre The heap must be nonempty.
+		    /// This function returns the item having minimum priority.
 		    /// \pre The heap must be non-empty.
 		    Item top() const {
 		      return _data[0].first;
+		    }
-		    /// \brief Returns the minimum priority relative to \c Compare.
+		    /// \brief The minimum priority.
 		    ///
 		    /// It returns the minimum priority relative to \c Compare.
 		    /// \pre The heap must be nonempty.
 		    /// This function returns the minimum priority.
 		    /// \pre The heap must be non-empty.
 		    Prio prio() const {
 		      return _data[0].second;
+		    }
-		    /// \brief Deletes the item with minimum priority relative to \c Compare.
+		    /// \brief Remove the item having minimum priority.
 		    ///
 		    /// This method deletes the item with minimum priority relative to \c
 		    /// Compare from the heap.
 		    /// This function removes the item having minimum priority.
 		    /// \pre The heap must be non-empty.
 		    void pop() {
 		      int n = _data.size()-1;
 		      _iim.set(_data[0].first, POST_HEAP);
 		      if (n > 0) {
 		        bubble_down(0, _data[n], n);
+		      }
 		      _data.pop_back();
+		    }
-		    /// \brief Deletes \c i from the heap.
+		    /// \brief Remove the given item from the heap.
 		    ///
 		    /// This method deletes item \c i from the heap.
 		    /// \param i The item to erase.
-		    /// \pre The item should be in the heap.
+		    /// This function removes the given item from the heap if it is
 		    /// already stored.
 		    /// \param i The item to delete.
 		    /// \pre \e i must be in the heap.
 		    void erase(const Item &i) {
 		      int h = _iim[i];
 		      int n = _data.size()-1;
 		      _iim.set(_data[h].first, POST_HEAP);
 		      if( h < n ) {
 		        if ( bubble_up(h, _data[n]) == h) {
 		          bubble_down(h, _data[n], n);
+		        }
+		      }
 		      _data.pop_back();
+		    }
 		    /// \brief Returns the priority of \c i.
 		    /// \brief The priority of the given item.
 		    ///
-		    /// This function returns the priority of item \c i.
+		    /// This function returns the priority of the given item.
 		    /// \param i The item.
-		    /// \pre \c i must be in the heap.
+		    /// \pre \e i must be in the heap.
 		    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.
 		    /// \brief Set the priority of an item or insert it, if it is
 		    /// not stored in the heap.
 		    ///
 		    /// 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.
 		    /// This method sets the priority of the given item if it is
 		    /// already stored in the heap. Otherwise it inserts the given
 		    /// item into the heap with the given priority.
 		    /// \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, Pair(i,p));
+		      }
 		      else {
 		        bubble_down(idx, Pair(i,p), _data.size());
+		      }
+		    }
-		    /// \brief Decreases the priority of \c i to \c p.
+		    /// \brief Decrease the priority of an item to the given value.
 		    ///
-		    /// This method decreases the priority of item \c i to \c p.
+		    /// This function decreases the priority of an item to the given value.
 		    /// \param i The item.
 		    /// \param p The priority.
 		    /// \pre \c i must be stored in the heap with priority at least \c
 		    /// p relative to \c Compare.
 		    /// \pre \e i must be stored in the heap with priority at least \e p.
 		    void decrease(const Item &i, const Prio &p) {
 		      int idx = _iim[i];
 		      bubble_up(idx, Pair(i,p));
+		    }
-		    /// \brief Increases the priority of \c i to \c p.
+		    /// \brief Increase the priority of an item to the given value.
 		    ///
-		    /// This method sets the priority of item \c i to \c p.
+		    /// This function increases the priority of an item to the given value.
 		    /// \param i The item.
 		    /// \param p The priority.
 		    /// \pre \c i must be stored in the heap with priority at most \c
 		    /// p relative to \c Compare.
 		    /// \pre \e i must be stored in the heap with priority at most \e p.
 		    void increase(const Item &i, const Prio &p) {
 		      int idx = _iim[i];
 		      bubble_down(idx, Pair(i,p), _data.size());
+		    }
 		    /// \brief Returns if \c item is in, has already been in, or has
 		    /// never been in the heap.
 		    /// \brief Return the state of an item.
 		    ///
 		    /// 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.
 		    /// This method returns \c PRE_HEAP if the given item has never
 		    /// been in the heap, \c IN_HEAP if it is in the heap at the moment,
 		    /// and \c POST_HEAP otherwise.
 		    /// In the latter case it is possible that the item will get back
 		    /// to the heap again.
 		    /// \param i The item.
 		    State state(const Item &i) const {
 		      int s = _iim[i];
 		      if( s>=0 )
 		        s=0;
 		      return State(s);
+		    }
-		    /// \brief Sets the state of the \c item in the heap.
+		    /// \brief Set the state of an item in the heap.
 		    ///
 		    /// Sets the state of the \c item in the heap. It can be used to
 		    /// manually clear the heap when it is important to achive the
-		    /// better time complexity.
+		    /// This function sets the state of the given item in the heap.
 		    /// It can be used to manually clear the heap when it is important
 		    /// to achive better time complexity.
 		    /// \param i The item.
 		    /// \param st The state. It should not be \c IN_HEAP.
 		    void state(const Item& i, State st) {
 		      switch (st) {
 		      case POST_HEAP:
 		      case PRE_HEAP:
 		        if (state(i) == IN_HEAP) {
 		          erase(i);
+		        }
 		        _iim[i] = st;
 		        break;
 		      case IN_HEAP:
 		        break;
+		      }
+		    }
-		    /// \brief Replaces an item in the heap.
+		    /// \brief Replace an item in the heap.
 		    ///
 		    /// The \c i item is replaced with \c j item. The \c i item should
 		    /// be in the heap, while the \c j should be out of the heap. The
 		    /// \c i item will out of the heap and \c j will be in the heap
 		    /// with the same prioriority as prevoiusly the \c i item.
 		    /// This function replaces item \c i with item \c j.
 		    /// Item \c i must be in the heap, while \c j must be out of the heap.
 		    /// After calling this method, item \c i will be out of the
 		    /// heap and \c j will be in the heap with the same prioriority
 		    /// as item \c i had before.
 		    void replace(const Item& i, const Item& j) {
 		      int idx = _iim[i];
 		      _iim.set(i, _iim[j]);
 		      _iim.set(j, idx);
 		      _data[idx].first = j;
+		    }
 		  }; // class BinHeap
 		} // namespace lemon
 		#endif // LEMON_BIN_HEAP_H

lemon/bucket_heap.h

Show inline comments

 		/* -*- mode: C++; indent-tabs-mode: nil; -*-
+		 *
 		 * This file is a part of LEMON, a generic C++ optimization library.
+		 *
 		 * Copyright (C) 2003-2009
 		 * 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_BUCKET_HEAP_H
 		#define LEMON_BUCKET_HEAP_H
 		///\ingroup auxdat
 		///\file
-		///\brief Bucket Heap implementation.
+		///\brief Bucket heap implementation.
 		#include <vector>
 		#include <utility>
 		#include <functional>
 		namespace lemon {
 		  namespace _bucket_heap_bits {
 		    template <bool MIN>
 		    struct DirectionTraits {
 		      static bool less(int left, int right) {
 		        return left < right;
+		      }
 		      static void increase(int& value) {
 		        ++value;
+		      }
 		    };
 		    template <>
 		    struct DirectionTraits<false> {
 		      static bool less(int left, int right) {
 		        return left > right;
+		      }
 		      static void increase(int& value) {
 		        --value;
+		      }
 		    };
+		  }
 		  /// \ingroup auxdat
 		  ///
-		  /// \brief A Bucket Heap implementation.
+		  /// \brief Bucket heap data structure.
 		  ///
 		  /// This class implements the \e bucket \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. The bucket heap is very simple implementation, it can store
 		  /// only integer priorities and it stores for each priority in the
 		  /// \f$ [0..C) \f$ range a list of items. So it should be used only when
-		  /// the priorities are small. It is not intended to use as dijkstra heap.
+		  /// This class implements the \e bucket \e heap data structure.
 		  /// It practically conforms to the \ref concepts::Heap "heap concept",
 		  /// but it has some limitations.
 		  ///
 		  /// \param IM A read and write Item int map, used internally
 		  /// to handle the cross references.
 		  /// \param MIN If the given parameter is false then instead of the
 		  /// minimum value the maximum can be retrivied with the top() and
-		  /// prio() member functions.
+		  /// The bucket heap is a very simple structure. It can store only
 		  /// \c int priorities and it maintains a list of items for each priority
 		  /// in the range <tt>[0..C)</tt>. So it should only be used when the
 		  /// priorities are small. It is not intended to use as a Dijkstra heap.
 		  ///
 		  /// \tparam IM A read-writable item map with \c int values, used
 		  /// internally to handle the cross references.
 		  /// \tparam MIN Indicate if the heap is a \e min-heap or a \e max-heap.
 		  /// The default is \e min-heap. If this parameter is set to \c false,
 		  /// then the comparison is reversed, so the top(), prio() and pop()
 		  /// functions deal with the item having maximum priority instead of the
 		  /// minimum.
 		  ///
 		  /// \sa SimpleBucketHeap
 		  template <typename IM, bool MIN = true>
 		  class BucketHeap {
 		  public:
 		    /// \e
 		    typedef typename IM::Key Item;
-		    /// \e
 		    /// Type of the item-int map.
 		    typedef IM ItemIntMap;
 		    /// Type of the priorities.
 		    typedef int Prio;
 		    /// \e
 		    typedef std::pair<Item, Prio> Pair;
 		    /// \e
 		    typedef IM ItemIntMap;
 		    /// Type of the items stored in the heap.
 		    typedef typename ItemIntMap::Key Item;
 		    /// Type of the item-priority pairs.
 		    typedef std::pair<Item,Prio> Pair;
 		  private:
 		    typedef _bucket_heap_bits::DirectionTraits<MIN> Direction;
 		  public:
-		    /// \brief Type to represent the items states.
+		    /// \brief Type to represent the states of the items.
 		    ///
 		    /// 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
 		    /// Each item has a state associated to it. It can 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 item-int map must be initialized in such way that it assigns
 		    /// \c PRE_HEAP (<tt>-1</tt>) to any element to be put in the heap.
 		    enum State {
 		      IN_HEAP = 0,    ///< = 0.
 		      PRE_HEAP = -1,  ///< = -1.
 		      POST_HEAP = -2  ///< = -2.
 		    };
 		  public:
-		    /// \brief The constructor.
 		    /// \brief Constructor.
 		    ///
 		    /// The constructor.
 		    /// \param map 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.
 		    /// Constructor.
 		    /// \param map A map that assigns \c int values to the items.
 		    /// It is used internally to handle the cross references.
 		    /// The assigned value must be \c PRE_HEAP (<tt>-1</tt>) for each item.
 		    explicit BucketHeap(ItemIntMap &map) : _iim(map), _minimum(0) {}
 		    /// The number of items stored in the heap.
+		    /// \brief The number of items stored in the heap.
 		    ///
-		    /// \brief Returns the number of items stored in the heap.
+		    /// This function returns the number of items stored in the heap.
 		    int size() const { return _data.size(); }
-		    /// \brief Checks if the heap stores no items.
+		    /// \brief Check if the heap is empty.
 		    ///
-		    /// Returns \c true if and only if the heap stores no items.
+		    /// This function returns \c true if the heap is empty.
 		    bool empty() const { return _data.empty(); }
-		    /// \brief Make empty this heap.
+		    /// \brief Make the heap empty.
 		    ///
 		    /// Make empty this heap. It does not change the cross reference
 		    /// map.  If you want to reuse a heap what is not surely empty you
 		    /// should first clear the heap and after that you should set the
 		    /// cross reference map for each item to \c PRE_HEAP.
 		    /// This functon makes the heap empty.
 		    /// It does not change the cross reference map. If you want to reuse
 		    /// a heap that is not surely empty, you should first clear it and
 		    /// then you should set the cross reference map to \c PRE_HEAP
 		    /// for each item.
 		    void clear() {
 		      _data.clear(); _first.clear(); _minimum = 0;
+		    }
 		  private:
 		    void relocate_last(int idx) {
 		      if (idx + 1 < int(_data.size())) {
 		        _data[idx] = _data.back();
 		        if (_data[idx].prev != -1) {
 		          _data[_data[idx].prev].next = idx;
 		        } else {
 		          _first[_data[idx].value] = idx;
+		        }
 		        if (_data[idx].next != -1) {
 		          _data[_data[idx].next].prev = idx;
+		        }
 		        _iim[_data[idx].item] = idx;
+		      }
 		      _data.pop_back();
+		    }
 		    void unlace(int idx) {
 		      if (_data[idx].prev != -1) {
 		        _data[_data[idx].prev].next = _data[idx].next;
 		      } else {
 		        _first[_data[idx].value] = _data[idx].next;
+		      }
 		      if (_data[idx].next != -1) {
 		        _data[_data[idx].next].prev = _data[idx].prev;
+		      }
+		    }
 		    void lace(int idx) {
 		      if (int(_first.size()) <= _data[idx].value) {
 		        _first.resize(_data[idx].value + 1, -1);
+		      }
 		      _data[idx].next = _first[_data[idx].value];
 		      if (_data[idx].next != -1) {
 		        _data[_data[idx].next].prev = idx;
+		      }
 		      _first[_data[idx].value] = idx;
 		      _data[idx].prev = -1;
+		    }
 		  public:
 		    /// \brief Insert a pair of item and priority into the heap.
 		    ///
-		    /// Adds \c p.first to the heap with priority \c p.second.
+		    /// This function inserts \c p.first to the heap with priority
 		    /// \c p.second.
 		    /// \param p The pair to insert.
 		    /// \pre \c p.first must not be stored in the heap.
 		    void push(const Pair& p) {
 		      push(p.first, p.second);
+		    }
 		    /// \brief Insert an item into the heap with the given priority.
 		    ///
-		    /// Adds \c i to the heap with priority \c p.
+		    /// This function inserts the given item into the heap with the
 		    /// given priority.
 		    /// \param i The item to insert.
 		    /// \param p The priority of the item.
 		    /// \pre \e i must not be stored in the heap.
 		    void push(const Item &i, const Prio &p) {
 		      int idx = _data.size();
 		      _iim[i] = idx;
 		      _data.push_back(BucketItem(i, p));
 		      lace(idx);
 		      if (Direction::less(p, _minimum)) {
 		        _minimum = p;
+		      }
+		    }
-		    /// \brief Returns the item with minimum priority.
+		    /// \brief Return the item having minimum priority.
 		    ///
 		    /// This method returns the item with minimum priority.
 		    /// \pre The heap must be nonempty.
 		    /// This function returns the item having minimum priority.
 		    /// \pre The heap must be non-empty.
 		    Item top() const {
 		      while (_first[_minimum] == -1) {
 		        Direction::increase(_minimum);
+		      }
 		      return _data[_first[_minimum]].item;
+		    }
-		    /// \brief Returns the minimum priority.
+		    /// \brief The minimum priority.
 		    ///
 		    /// It returns the minimum priority.
 		    /// \pre The heap must be nonempty.
 		    /// This function returns the minimum priority.
 		    /// \pre The heap must be non-empty.
 		    Prio prio() const {
 		      while (_first[_minimum] == -1) {
 		        Direction::increase(_minimum);
+		      }
 		      return _minimum;
+		    }
-		    /// \brief Deletes the item with minimum priority.
+		    /// \brief Remove the item having minimum priority.
 		    ///
-		    /// This method deletes the item with minimum priority from the heap.
+		    /// This function removes the item having minimum priority.
 		    /// \pre The heap must be non-empty.
 		    void pop() {
 		      while (_first[_minimum] == -1) {
 		        Direction::increase(_minimum);
+		      }
 		      int idx = _first[_minimum];
 		      _iim[_data[idx].item] = -2;
 		      unlace(idx);
 		      relocate_last(idx);
+		    }
-		    /// \brief Deletes \c i from the heap.
+		    /// \brief Remove the given item 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.
+		    /// This function removes the given item from the heap if it is
 		    /// already stored.
 		    /// \param i The item to delete.
 		    /// \pre \e i must be in the heap.
 		    void erase(const Item &i) {
 		      int idx = _iim[i];
 		      _iim[_data[idx].item] = -2;
 		      unlace(idx);
 		      relocate_last(idx);
+		    }
 		    /// \brief Returns the priority of \c i.
 		    /// \brief The priority of the given item.
 		    ///
 		    /// This function returns the priority of item \c i.
 		    /// \pre \c i must be in the heap.
 		    /// This function returns the priority of the given item.
 		    /// \param i The item.
 		    /// \pre \e i must be in the heap.
 		    Prio operator[](const Item &i) const {
 		      int idx = _iim[i];
 		      return _data[idx].value;
+		    }
 		    /// \brief \c i gets to the heap with priority \c p independently
 		    /// if \c i was already there.
 		    /// \brief Set the priority of an item or insert it, if it is
 		    /// not stored in the heap.
 		    ///
 		    /// 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.
 		    /// This method sets the priority of the given item if it is
 		    /// already stored in the heap. Otherwise it inserts the given
 		    /// item into the heap with the given priority.
 		    /// \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 (Direction::less(p, _data[idx].value)) {
 		        decrease(i, p);
 		      } else {
 		        increase(i, p);
+		      }
+		    }
-		    /// \brief Decreases the priority of \c i to \c p.
+		    /// \brief Decrease the priority of an item to the given value.
 		    ///
 		    /// 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.
+		    /// This function decreases the priority of an item to the given value.
 		    /// \param i The item.
 		    /// \param p The priority.
 		    /// \pre \e i must be stored in the heap with priority at least \e p.
 		    void decrease(const Item &i, const Prio &p) {
 		      int idx = _iim[i];
 		      unlace(idx);
 		      _data[idx].value = p;
 		      if (Direction::less(p, _minimum)) {
 		        _minimum = p;
+		      }
 		      lace(idx);
+		    }
-		    /// \brief Increases the priority of \c i to \c p.
+		    /// \brief Increase the priority of an item to the given value.
 		    ///
 		    /// 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.
+		    /// This function increases the priority of an item to the given value.
 		    /// \param i The item.
 		    /// \param p The priority.
 		    /// \pre \e i must be stored in the heap with priority at most \e p.
 		    void increase(const Item &i, const Prio &p) {
 		      int idx = _iim[i];
 		      unlace(idx);
 		      _data[idx].value = p;
 		      lace(idx);
+		    }
 		    /// \brief Returns if \c item is in, has already been in, or has
 		    /// never been in the heap.
 		    /// \brief Return the state of an item.
 		    ///
 		    /// 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.
 		    /// This method returns \c PRE_HEAP if the given item has never
 		    /// been in the heap, \c IN_HEAP if it is in the heap at the moment,
 		    /// and \c POST_HEAP otherwise.
 		    /// In the latter case it is possible that the item will get back
 		    /// to the heap again.
 		    /// \param i The item.
 		    State state(const Item &i) const {
 		      int idx = _iim[i];
 		      if (idx >= 0) idx = 0;
 		      return State(idx);
+		    }
-		    /// \brief Sets the state of the \c item in the heap.
+		    /// \brief Set the state of an item in the heap.
 		    ///
 		    /// Sets the state of the \c item in the heap. It can be used to
 		    /// manually clear the heap when it is important to achive the
-		    /// better time complexity.
+		    /// This function sets the state of the given item in the heap.
 		    /// It can be used to manually clear the heap when it is important
 		    /// to achive better time complexity.
 		    /// \param i The item.
 		    /// \param st The state. It should not be \c IN_HEAP.
 		    void state(const Item& i, State st) {
 		      switch (st) {
 		      case POST_HEAP:
 		      case PRE_HEAP:
 		        if (state(i) == IN_HEAP) {
 		          erase(i);
+		        }
 		        _iim[i] = st;
 		        break;
 		      case IN_HEAP:
 		        break;
+		      }
+		    }
 		  private:
 		    struct BucketItem {
 		      BucketItem(const Item& _item, int _value)
 		        : item(_item), value(_value) {}
 		      Item item;
 		      int value;
 		      int prev, next;
 		    };
 		    ItemIntMap& _iim;
 		    std::vector<int> _first;
 		    std::vector<BucketItem> _data;
 		    mutable int _minimum;
 		  }; // class BucketHeap
 		  /// \ingroup auxdat
 		  ///
-		  /// \brief A Simplified Bucket Heap implementation.
+		  /// \brief Simplified bucket heap data structure.
 		  ///
 		  /// This class implements a simplified \e bucket \e heap data
 		  /// structure.  It does not provide some functionality but it faster
 		  /// and simplier data structure than the BucketHeap. The main
 		  /// difference is that the BucketHeap stores for every key a double
 		  /// linked list while this class stores just simple lists. In the
 		  /// other way it does not support erasing each elements just the
 		  /// minimal and it does not supports key increasing, decreasing.
 		  /// structure. It does not provide some functionality, but it is
 		  /// faster and simpler than BucketHeap. The main difference is
 		  /// that BucketHeap stores a doubly-linked list for each key while
 		  /// this class stores only simply-linked lists. It supports erasing
 		  /// only for the item having minimum priority and it does not support
 		  /// key increasing and decreasing.
 		  ///
 		  /// \param IM A read and write Item int map, used internally
 		  /// to handle the cross references.
 		  /// \param MIN If the given parameter is false then instead of the
 		  /// minimum value the maximum can be retrivied with the top() and
-		  /// prio() member functions.
+		  /// Note that this implementation does not conform to the
 		  /// \ref concepts::Heap "heap concept" due to the lack of some
 		  /// functionality.
 		  ///
 		  /// \tparam IM A read-writable item map with \c int values, used
 		  /// internally to handle the cross references.
 		  /// \tparam MIN Indicate if the heap is a \e min-heap or a \e max-heap.
 		  /// The default is \e min-heap. If this parameter is set to \c false,
 		  /// then the comparison is reversed, so the top(), prio() and pop()
 		  /// functions deal with the item having maximum priority instead of the
 		  /// minimum.
 		  ///
 		  /// \sa BucketHeap
 		  template <typename IM, bool MIN = true >
 		  class SimpleBucketHeap {
 		  public:
-		    typedef typename IM::Key Item;
 		    /// Type of the item-int map.
 		    typedef IM ItemIntMap;
 		    /// Type of the priorities.
 		    typedef int Prio;
 		    typedef std::pair<Item, Prio> Pair;
 		    typedef IM ItemIntMap;
 		    /// Type of the items stored in the heap.
 		    typedef typename ItemIntMap::Key Item;
 		    /// Type of the item-priority pairs.
 		    typedef std::pair<Item,Prio> Pair;
 		  private:
 		    typedef _bucket_heap_bits::DirectionTraits<MIN> Direction;
 		  public:
-		    /// \brief Type to represent the items states.
+		    /// \brief Type to represent the states of the items.
 		    ///
 		    /// 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
 		    /// Each item has a state associated to it. It can 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 item-int map must be initialized in such way that it assigns
 		    /// \c PRE_HEAP (<tt>-1</tt>) to any element to be put in the heap.
 		    enum State {
 		      IN_HEAP = 0,    ///< = 0.
 		      PRE_HEAP = -1,  ///< = -1.
 		      POST_HEAP = -2  ///< = -2.
 		    };
 		  public:
-		    /// \brief The constructor.
+		    /// \brief Constructor.
 		    ///
 		    /// The constructor.
 		    /// \param map 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.
 		    /// Constructor.
 		    /// \param map A map that assigns \c int values to the items.
 		    /// It is used internally to handle the cross references.
 		    /// The assigned value must be \c PRE_HEAP (<tt>-1</tt>) for each item.
 		    explicit SimpleBucketHeap(ItemIntMap &map)
 		      : _iim(map), _free(-1), _num(0), _minimum(0) {}
-		    /// \brief Returns the number of items stored in the heap.
+		    /// \brief The number of items stored in the heap.
 		    ///
-		    /// The number of items stored in the heap.
+		    /// This function returns the number of items stored in the heap.
 		    int size() const { return _num; }
-		    /// \brief Checks if the heap stores no items.
+		    /// \brief Check if the heap is empty.
 		    ///
-		    /// Returns \c true if and only if the heap stores no items.
+		    /// This function returns \c true if the heap is empty.
 		    bool empty() const { return _num == 0; }
-		    /// \brief Make empty this heap.
+		    /// \brief Make the heap empty.
 		    ///
 		    /// Make empty this heap. It does not change the cross reference
 		    /// map.  If you want to reuse a heap what is not surely empty you
 		    /// should first clear the heap and after that you should set the
 		    /// cross reference map for each item to \c PRE_HEAP.
 		    /// This functon makes the heap empty.
 		    /// It does not change the cross reference map. If you want to reuse
 		    /// a heap that is not surely empty, you should first clear it and
 		    /// then you should set the cross reference map to \c PRE_HEAP
 		    /// for each item.
 		    void clear() {
 		      _data.clear(); _first.clear(); _free = -1; _num = 0; _minimum = 0;
+		    }
 		    /// \brief Insert a pair of item and priority into the heap.
 		    ///
-		    /// Adds \c p.first to the heap with priority \c p.second.
+		    /// This function inserts \c p.first to the heap with priority
 		    /// \c p.second.
 		    /// \param p The pair to insert.
 		    /// \pre \c p.first must not be stored in the heap.
 		    void push(const Pair& p) {
 		      push(p.first, p.second);
+		    }
 		    /// \brief Insert an item into the heap with the given priority.
 		    ///
-		    /// Adds \c i to the heap with priority \c p.
+		    /// This function inserts the given item into the heap with the
 		    /// given priority.
 		    /// \param i The item to insert.
 		    /// \param p The priority of the item.
 		    /// \pre \e i must not be stored in the heap.
 		    void push(const Item &i, const Prio &p) {
 		      int idx;
 		      if (_free == -1) {
 		        idx = _data.size();
 		        _data.push_back(BucketItem(i));
 		      } else {
 		        idx = _free;
 		        _free = _data[idx].next;
 		        _data[idx].item = i;
+		      }
 		      _iim[i] = idx;
 		      if (p >= int(_first.size())) _first.resize(p + 1, -1);
 		      _data[idx].next = _first[p];
 		      _first[p] = idx;
 		      if (Direction::less(p, _minimum)) {
 		        _minimum = p;
+		      }
 		      ++_num;
+		    }
-		    /// \brief Returns the item with minimum priority.
+		    /// \brief Return the item having minimum priority.
 		    ///
 		    /// This method returns the item with minimum priority.
 		    /// \pre The heap must be nonempty.
 		    /// This function returns the item having minimum priority.
 		    /// \pre The heap must be non-empty.
 		    Item top() const {
 		      while (_first[_minimum] == -1) {
 		        Direction::increase(_minimum);
+		      }
 		      return _data[_first[_minimum]].item;
+		    }
-		    /// \brief Returns the minimum priority.
+		    /// \brief The minimum priority.
 		    ///
 		    /// It returns the minimum priority.
 		    /// \pre The heap must be nonempty.
 		    /// This function returns the minimum priority.
 		    /// \pre The heap must be non-empty.
 		    Prio prio() const {
 		      while (_first[_minimum] == -1) {
 		        Direction::increase(_minimum);
+		      }
 		      return _minimum;
+		    }
-		    /// \brief Deletes the item with minimum priority.
+		    /// \brief Remove the item having minimum priority.
 		    ///
-		    /// This method deletes the item with minimum priority from the heap.
+		    /// This function removes the item having minimum priority.
 		    /// \pre The heap must be non-empty.
 		    void pop() {
 		      while (_first[_minimum] == -1) {
 		        Direction::increase(_minimum);
+		      }
 		      int idx = _first[_minimum];
 		      _iim[_data[idx].item] = -2;
 		      _first[_minimum] = _data[idx].next;
 		      _data[idx].next = _free;
 		      _free = idx;
 		      --_num;
+		    }
-		    /// \brief Returns the priority of \c i.
+		    /// \brief The priority of the given item.
 		    ///
 		    /// This function returns the priority of item \c i.
 		    /// \warning This operator is not a constant time function
 		    /// because it scans the whole data structure to find the proper
 		    /// value.
-		    /// \pre \c i must be in the heap.
+		    /// This function returns the priority of the given item.
 		    /// \param i The item.
 		    /// \pre \e i must be in the heap.
 		    /// \warning This operator is not a constant time function because
 		    /// it scans the whole data structure to find the proper value.
 		    Prio operator[](const Item &i) const {
 		      for (int k = 0; k < _first.size(); ++k) {
+		      for (int k = 0; k < int(_first.size()); ++k) {
 		        int idx = _first[k];
 		        while (idx != -1) {
 		          if (_data[idx].item == i) {
 		            return k;
+		          }
 		          idx = _data[idx].next;
+		        }
+		      }
 		      return -1;
+		    }
 		    /// \brief Returns if \c item is in, has already been in, or has
 		    /// never been in the heap.
 		    /// \brief Return the state of an item.
 		    ///
 		    /// 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.
 		    /// This method returns \c PRE_HEAP if the given item has never
 		    /// been in the heap, \c IN_HEAP if it is in the heap at the moment,
 		    /// and \c POST_HEAP otherwise.
 		    /// In the latter case it is possible that the item will get back
 		    /// to the heap again.
 		    /// \param i The item.
 		    State state(const Item &i) const {
 		      int idx = _iim[i];
 		      if (idx >= 0) idx = 0;
 		      return State(idx);
+		    }
 		  private:
 		    struct BucketItem {
 		      BucketItem(const Item& _item)
 		        : item(_item) {}
 		      Item item;
 		      int next;
 		    };
 		    ItemIntMap& _iim;
 		    std::vector<int> _first;
 		    std::vector<BucketItem> _data;
 		    int _free, _num;
 		    mutable int _minimum;
 		  }; // class SimpleBucketHeap
+		}
 		#endif

lemon/concepts/heap.h

Show inline comments

 		/* -*- mode: C++; indent-tabs-mode: nil; -*-
+		 *
 		 * This file is a part of LEMON, a generic C++ optimization library.
+		 *
 		 * Copyright (C) 2003-2009
 		 * 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_CONCEPTS_HEAP_H
 		#define LEMON_CONCEPTS_HEAP_H
 		///\ingroup concept
 		///\file
 		///\brief The concept of heaps.
 		#ifndef LEMON_CONCEPTS_HEAP_H
 		#define LEMON_CONCEPTS_HEAP_H
 		#include <lemon/core.h>
 		#include <lemon/concept_check.h>
 		namespace lemon {
 		  namespace concepts {
 		    /// \addtogroup concept
 		    /// @{
 		    /// \brief The heap concept.
 		    ///
 		    /// Concept class describing the main interface of heaps. 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. In a heap one can change the priority of an
-		    /// item, add or erase an item, etc.
+		    /// This concept class describes the main interface of heaps.
 		    /// The various heap structures are efficient
 		    /// implementations of the abstract data type \e priority \e queue.
 		    /// They store items with specified values called \e priorities
 		    /// in such a way that finding and removing the item with minimum
 		    /// priority are efficient. The basic operations are adding and
 		    /// erasing items, changing the priority of an item, etc.
 		    ///
 		    /// \tparam PR Type of the priority of the items.
 		    /// \tparam IM A read and writable item map with int values, used
 		    /// Heaps are crucial in several algorithms, such as Dijkstra and Prim.
 		    /// Any class that conforms to this concept can be used easily in such
 		    /// algorithms.
 		    ///
 		    /// \tparam PR Type of the priorities of the items.
 		    /// \tparam IM A read-writable item map with \c int values, used
 		    /// internally to handle the cross references.
-		    /// \tparam Comp A functor class for the ordering of the priorities.
+		    /// \tparam CMP A functor class for comparing the priorities.
 		    /// The default is \c std::less<PR>.
 		#ifdef DOXYGEN
-		    template <typename PR, typename IM, typename Comp = std::less<PR> >
+		    template <typename PR, typename IM, typename CMP>
 		#else
 		    template <typename PR, typename IM>
+		    template <typename PR, typename IM, typename CMP = std::less<PR> >
 		#endif
 		    class Heap {
 		    public:
 		      /// Type of the item-int map.
 		      typedef IM ItemIntMap;
 		      /// Type of the priorities.
 		      typedef PR Prio;
 		      /// Type of the items stored in the heap.
 		      typedef typename ItemIntMap::Key Item;
 		      /// \brief Type to represent the states of the items.
 		      ///
 		      /// Each item has a state associated to it. It can be "in heap",
 		      /// "pre heap" or "post heap". The later two are indifferent
 		      /// from the point of view of the heap, but may be useful for
-		      /// the user.
+		      /// "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 item-int map must be initialized in such way that it assigns
 		      /// \c PRE_HEAP (<tt>-1</tt>) to any element to be put in the heap.
 		      enum State {
 		        IN_HEAP = 0,    ///< = 0. The "in heap" state constant.
 		        PRE_HEAP = -1,  ///< = -1. The "pre heap" state constant.
 		        POST_HEAP = -2  ///< = -2. The "post heap" state constant.
 		        PRE_HEAP = -1,  ///< = -1. The "pre-heap" state constant.
 		        POST_HEAP = -2  ///< = -2. The "post-heap" state constant.
 		      };
-		      /// \brief The constructor.
+		      /// \brief Constructor.
 		      ///
-		      /// The constructor.
+		      /// Constructor.
 		      /// \param map A map that assigns \c int values to keys of type
 		      /// \c Item. It is used internally by the heap implementations to
 		      /// handle the cross references. The assigned value must be
-		      /// \c PRE_HEAP (<tt>-1</tt>) for every item.
+		      /// \c PRE_HEAP (<tt>-1</tt>) for each item.
 		      explicit Heap(ItemIntMap &map) {}
 		      /// \brief Constructor.
 		      ///
 		      /// Constructor.
 		      /// \param map A map that assigns \c int values to keys of type
 		      /// \c Item. It is used internally by the heap implementations to
 		      /// handle the cross references. The assigned value must be
 		      /// \c PRE_HEAP (<tt>-1</tt>) for each item.
 		      /// \param comp The function object used for comparing the priorities.
 		      explicit Heap(ItemIntMap &map, const CMP &comp) {}
 		      /// \brief The number of items stored in the heap.
 		      ///
-		      /// Returns the number of items stored in the heap.
+		      /// This function returns the number of items stored in the heap.
 		      int size() const { return 0; }
-		      /// \brief Checks if the heap is empty.
+		      /// \brief Check if the heap is empty.
 		      ///
-		      /// Returns \c true if the heap is empty.
+		      /// This function returns \c true if the heap is empty.
 		      bool empty() const { return false; }
-		      /// \brief Makes the heap empty.
+		      /// \brief Make the heap empty.
 		      ///
 		      /// Makes the heap empty.
 		      void clear();
 		      /// This functon makes the heap empty.
 		      /// It does not change the cross reference map. If you want to reuse
 		      /// a heap that is not surely empty, you should first clear it and
 		      /// then you should set the cross reference map to \c PRE_HEAP
 		      /// for each item.
 		      void clear() {}
-		      /// \brief Inserts an item into the heap with the given priority.
+		      /// \brief Insert an item into the heap with the given priority.
 		      ///
-		      /// Inserts the given item into the heap with the given priority.
+		      /// This function inserts the given item into the heap with the
 		      /// given priority.
 		      /// \param i The item to insert.
 		      /// \param p The priority of the item.
 		      /// \pre \e i must not be stored in the heap.
 		      void push(const Item &i, const Prio &p) {}
-		      /// \brief Returns the item having minimum priority.
+		      /// \brief Return the item having minimum priority.
 		      ///
-		      /// Returns the item having minimum priority.
+		      /// This function returns the item having minimum priority.
 		      /// \pre The heap must be non-empty.
 		      Item top() const {}
 		      /// \brief The minimum priority.
 		      ///
-		      /// Returns the minimum priority.
+		      /// This function returns the minimum priority.
 		      /// \pre The heap must be non-empty.
 		      Prio prio() const {}
-		      /// \brief Removes the item having minimum priority.
+		      /// \brief Remove the item having minimum priority.
 		      ///
-		      /// Removes the item having minimum priority.
+		      /// This function removes the item having minimum priority.
 		      /// \pre The heap must be non-empty.
 		      void pop() {}
-		      /// \brief Removes an item from the heap.
+		      /// \brief Remove the given item from the heap.
 		      ///
-		      /// Removes the given item from the heap if it is already stored.
+		      /// This function removes the given item from the heap if it is
 		      /// already stored.
 		      /// \param i The item to delete.
 		      /// \pre \e i must be in the heap.
 		      void erase(const Item &i) {}
-		      /// \brief The priority of an item.
+		      /// \brief The priority of the given item.
 		      ///
-		      /// Returns the priority of the given item.
+		      /// This function returns the priority of the given item.
 		      /// \param i The item.
-		      /// \pre \c i must be in the heap.
+		      /// \pre \e i must be in the heap.
 		      Prio operator[](const Item &i) const {}
-		      /// \brief Sets the priority of an item or inserts it, if it is
+		      /// \brief Set the priority of an item or insert it, if it is
 		      /// not stored in the heap.
 		      ///
 		      /// This method sets the priority of the given item if it is
 		      /// already stored in the heap.
 		      /// Otherwise it inserts the given item with the given priority.
 		      /// already stored in the heap. Otherwise it inserts the given
 		      /// item into the heap with the given priority.
 		      ///
 		      /// \param i The item.
 		      /// \param p The priority.
 		      void set(const Item &i, const Prio &p) {}
-		      /// \brief Decreases the priority of an item to the given value.
+		      /// \brief Decrease the priority of an item to the given value.
 		      ///
-		      /// Decreases the priority of an item to the given value.
+		      /// This function decreases the priority of an item to the given value.
 		      /// \param i The item.
 		      /// \param p The priority.
-		      /// \pre \c i must be stored in the heap with priority at least \c p.
+		      /// \pre \e i must be stored in the heap with priority at least \e p.
 		      void decrease(const Item &i, const Prio &p) {}
-		      /// \brief Increases the priority of an item to the given value.
+		      /// \brief Increase the priority of an item to the given value.
 		      ///
-		      /// Increases the priority of an item to the given value.
+		      /// This function increases the priority of an item to the given value.
 		      /// \param i The item.
 		      /// \param p The priority.
-		      /// \pre \c i must be stored in the heap with priority at most \c p.
+		      /// \pre \e i must be stored in the heap with priority at most \e p.
 		      void increase(const Item &i, const Prio &p) {}
 		      /// \brief Returns if an item is in, has already been in, or has
 		      /// never been in the heap.
 		      /// \brief Return the state of an item.
 		      ///
 		      /// This method returns \c PRE_HEAP if the given item has never
 		      /// been in the heap, \c IN_HEAP if it is in the heap at the moment,
 		      /// and \c POST_HEAP otherwise.
 		      /// In the latter case it is possible that the item will get back
 		      /// to the heap again.
 		      /// \param i The item.
 		      State state(const Item &i) const {}
-		      /// \brief Sets the state of an item in the heap.
+		      /// \brief Set the state of an item in the heap.
 		      ///
 		      /// Sets the state of the given item in the heap. It can be used
 		      /// to manually clear the heap when it is important to achive the
-		      /// better time complexity.
+		      /// This function sets the state of the given item in the heap.
 		      /// It can be used to manually clear the heap when it is important
 		      /// to achive better time complexity.
 		      /// \param i The item.
 		      /// \param st The state. It should not be \c IN_HEAP.
 		      void state(const Item& i, State st) {}
 		      template <typename _Heap>
 		      struct Constraints {
 		      public:
 		        void constraints() {
 		          typedef typename _Heap::Item OwnItem;
 		          typedef typename _Heap::Prio OwnPrio;
 		          typedef typename _Heap::State OwnState;
 		          Item item;
 		          Prio prio;
 		          item=Item();
 		          prio=Prio();
 		          ignore_unused_variable_warning(item);
 		          ignore_unused_variable_warning(prio);
 		          OwnItem own_item;
 		          OwnPrio own_prio;
 		          OwnState own_state;
 		          own_item=Item();
 		          own_prio=Prio();
 		          ignore_unused_variable_warning(own_item);
 		          ignore_unused_variable_warning(own_prio);
 		          ignore_unused_variable_warning(own_state);
 		          _Heap heap1(map);
 		          _Heap heap2 = heap1;
 		          ignore_unused_variable_warning(heap1);
 		          ignore_unused_variable_warning(heap2);
 		          int s = heap.size();
 		          ignore_unused_variable_warning(s);
 		          bool e = heap.empty();
 		          ignore_unused_variable_warning(e);
 		          prio = heap.prio();
 		          item = heap.top();
 		          prio = heap[item];
 		          own_prio = heap.prio();
 		          own_item = heap.top();
 		          own_prio = heap[own_item];
 		          heap.push(item, prio);
 		          heap.push(own_item, own_prio);

lemon/fib_heap.h

Show inline comments

 		/* -*- mode: C++; indent-tabs-mode: nil; -*-
+		 *
 		 * This file is a part of LEMON, a generic C++ optimization library.
+		 *
 		 * Copyright (C) 2003-2009
 		 * 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_FIB_HEAP_H
 		#define LEMON_FIB_HEAP_H
 		///\file
 		///\ingroup auxdat
-		///\brief Fibonacci Heap implementation.
+		///\brief Fibonacci heap implementation.
 		#include <vector>
 		#include <utility>
 		#include <functional>
 		#include <lemon/math.h>
 		namespace lemon {
 		  /// \ingroup auxdat
 		  ///
-		  ///\brief Fibonacci Heap.
+		  /// \brief Fibonacci heap data structure.
 		  ///
 		  ///This class implements the \e Fibonacci \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 CMP specifies the ordering of the priorities. In a heap
-		  ///one can change the priority of an item, add or erase an item, etc.
+		  /// This class implements the \e Fibonacci \e heap data structure.
 		  /// It fully conforms to the \ref concepts::Heap "heap concept".
 		  ///
 		  ///The methods \ref increase and \ref erase are not efficient in a Fibonacci
 		  ///heap. In case of many calls to these operations, it is better to use a
-		  ///\ref BinHeap "binary heap".
+		  /// The methods \ref increase() and \ref erase() are not efficient in a
 		  /// Fibonacci heap. In case of many calls of these operations, it is
 		  /// better to use other heap structure, e.g. \ref BinHeap "binary heap".
 		  ///
 		  ///\param PRIO Type of the priority of the items.
 		  ///\param IM A read and writable Item int map, used internally
 		  ///to handle the cross references.
 		  ///\param CMP A class for the ordering of the priorities. The
 		  ///default is \c std::less<PRIO>.
 		  ///
 		  ///\sa BinHeap
 		  ///\sa Dijkstra
 		  /// \tparam PR Type of the priorities of the items.
 		  /// \tparam IM A read-writable item map with \c int values, used
 		  /// internally to handle the cross references.
 		  /// \tparam CMP A functor class for comparing the priorities.
 		  /// The default is \c std::less<PR>.
 		#ifdef DOXYGEN
-		  template <typename PRIO, typename IM, typename CMP>
+		  template <typename PR, typename IM, typename CMP>
 		#else
-		  template <typename PRIO, typename IM, typename CMP = std::less<PRIO> >
+		  template <typename PR, typename IM, typename CMP = std::less<PR> >
 		#endif
 		  class FibHeap {
 		  public:
-		    ///\e
 		    /// Type of the item-int map.
 		    typedef IM ItemIntMap;
 		    ///\e
 		    typedef PRIO Prio;
-		    ///\e
+		    /// Type of the priorities.
 		    typedef PR Prio;
 		    /// Type of the items stored in the heap.
 		    typedef typename ItemIntMap::Key Item;
-		    ///\e
+		    /// Type of the item-priority pairs.
 		    typedef std::pair<Item,Prio> Pair;
-		    ///\e
+		    /// Functor type for comparing the priorities.
 		    typedef CMP Compare;
 		  private:
 		    class Store;
 		    std::vector<Store> _data;
 		    int _minimum;
 		    ItemIntMap &_iim;
 		    Compare _comp;
 		    int _num;
 		  public:
-		    /// \brief Type to represent the items states.
+		    /// \brief Type to represent the states of the items.
 		    ///
 		    /// 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
 		    /// Each item has a state associated to it. It can 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 item-int map must be initialized in such way that it assigns
 		    /// \c PRE_HEAP (<tt>-1</tt>) to any element to be put in the heap.
 		    enum State {
 		      IN_HEAP = 0,    ///< = 0.
 		      PRE_HEAP = -1,  ///< = -1.
 		      POST_HEAP = -2  ///< = -2.
 		    };
-		    /// \brief The constructor
+		    /// \brief Constructor.
 		    ///
 		    /// \c map should be given to the constructor, since it is
 		    ///   used internally to handle the cross references.
 		    /// Constructor.
 		    /// \param map A map that assigns \c int values to the items.
 		    /// It is used internally to handle the cross references.
 		    /// The assigned value must be \c PRE_HEAP (<tt>-1</tt>) for each item.
 		    explicit FibHeap(ItemIntMap &map)
 		      : _minimum(0), _iim(map), _num() {}
-		    /// \brief The constructor
+		    /// \brief Constructor.
 		    ///
 		    /// \c map should be given to the constructor, since it is used
 		    /// internally to handle the cross references. \c comp is an
-		    /// object for ordering of the priorities.
+		    /// Constructor.
 		    /// \param map A map that assigns \c int values to the items.
 		    /// It is used internally to handle the cross references.
 		    /// The assigned value must be \c PRE_HEAP (<tt>-1</tt>) for each item.
 		    /// \param comp The function object used for comparing the priorities.
 		    FibHeap(ItemIntMap &map, const Compare &comp)
 		      : _minimum(0), _iim(map), _comp(comp), _num() {}
 		    /// \brief The number of items stored in the heap.
 		    ///
-		    /// Returns the number of items stored in the heap.
+		    /// This function returns the number of items stored in the heap.
 		    int size() const { return _num; }
-		    /// \brief Checks if the heap stores no items.
+		    /// \brief Check if the heap is empty.
 		    ///
-		    ///   Returns \c true if and only if the heap stores no items.
+		    /// This function returns \c true if the heap is empty.
 		    bool empty() const { return _num==0; }
-		    /// \brief Make empty this heap.
+		    /// \brief Make the heap empty.
 		    ///
 		    /// Make empty this heap. It does not change the cross reference
 		    /// map.  If you want to reuse a heap what is not surely empty you
 		    /// should first clear the heap and after that you should set the
 		    /// cross reference map for each item to \c PRE_HEAP.
 		    /// This functon makes the heap empty.
 		    /// It does not change the cross reference map. If you want to reuse
 		    /// a heap that is not surely empty, you should first clear it and
 		    /// then you should set the cross reference map to \c PRE_HEAP
 		    /// for each item.
 		    void clear() {
 		      _data.clear(); _minimum = 0; _num = 0;
+		    }
 		    /// \brief \c item gets to the heap with priority \c value independently
 		    /// if \c item was already there.
 		    /// \brief Insert an item into the heap with the given priority.
 		    ///
 		    /// This method calls \ref push(\c item, \c value) if \c item is not
 		    /// stored in the heap and it calls \ref decrease(\c item, \c value) or
 		    /// \ref increase(\c item, \c value) otherwise.
 		    void set (const Item& item, const Prio& value) {
 		      int i=_iim[item];
 		      if ( i >= 0 && _data[i].in ) {
 		        if ( _comp(value, _data[i].prio) ) decrease(item, value);
 		        if ( _comp(_data[i].prio, value) ) increase(item, value);
 		      } else push(item, value);
+		    }
 		    /// \brief Adds \c item to the heap with priority \c value.
 		    ///
 		    /// Adds \c item to the heap with priority \c value.
 		    /// \pre \c item must not be stored in the heap.
 		    void push (const Item& item, const Prio& value) {
 		    /// This function inserts the given item into the heap with the
 		    /// given priority.
 		    /// \param item The item to insert.
 		    /// \param prio The priority of the item.
 		    /// \pre \e item must not be stored in the heap.
 		    void push (const Item& item, const Prio& prio) {
 		      int i=_iim[item];
 		      if ( i < 0 ) {
 		        int s=_data.size();
 		        _iim.set( item, s );
 		        Store st;
 		        st.name=item;
 		        _data.push_back(st);
 		        i=s;
 		      } else {
 		        _data[i].parent=_data[i].child=-1;
 		        _data[i].degree=0;
 		        _data[i].in=true;
 		        _data[i].marked=false;
+		      }
 		      if ( _num ) {
 		        _data[_data[_minimum].right_neighbor].left_neighbor=i;
 		        _data[i].right_neighbor=_data[_minimum].right_neighbor;
 		        _data[_minimum].right_neighbor=i;
 		        _data[i].left_neighbor=_minimum;
-		        if ( _comp( value, _data[_minimum].prio) ) _minimum=i;
+		        if ( _comp( prio, _data[_minimum].prio) ) _minimum=i;
 		      } else {
 		        _data[i].right_neighbor=_data[i].left_neighbor=i;
 		        _minimum=i;
+		      }
-		      _data[i].prio=value;
+		      _data[i].prio=prio;
 		      ++_num;
+		    }
-		    /// \brief Returns the item with minimum priority relative to \c Compare.
+		    /// \brief Return the item having minimum priority.
 		    ///
 		    /// This method returns the item with minimum priority relative to \c
 		    /// Compare.
-		    /// \pre The heap must be nonempty.
+		    /// This function returns the item having minimum priority.
 		    /// \pre The heap must be non-empty.
 		    Item top() const { return _data[_minimum].name; }
-		    /// \brief Returns the minimum priority relative to \c Compare.
+		    /// \brief The minimum priority.
 		    ///
 		    /// It returns the minimum priority relative to \c Compare.
 		    /// \pre The heap must be nonempty.
-		    const Prio& prio() const { return _data[_minimum].prio; }
+		    /// This function returns the minimum priority.
 		    /// \pre The heap must be non-empty.
 		    Prio prio() const { return _data[_minimum].prio; }
-		    /// \brief Returns the priority of \c item.
+		    /// \brief Remove the item having minimum priority.
 		    ///
 		    /// It returns the priority of \c item.
 		    /// \pre \c item must be in the heap.
 		    const Prio& operator[](const Item& item) const {
 		      return _data[_iim[item]].prio;
+		    }
 		    /// \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.
 		    /// This function removes the item having minimum priority.
 		    /// \pre The heap must be non-empty.
 		    void pop() {
 		      /*The first case is that there are only one root.*/
 		      if ( _data[_minimum].left_neighbor==_minimum ) {
 		        _data[_minimum].in=false;
 		        if ( _data[_minimum].degree!=0 ) {
 		          makeroot(_data[_minimum].child);
 		          _minimum=_data[_minimum].child;
 		          balance();
+		        }
 		      } else {
 		        int right=_data[_minimum].right_neighbor;
 		        unlace(_minimum);
 		        _data[_minimum].in=false;
 		        if ( _data[_minimum].degree > 0 ) {
 		          int left=_data[_minimum].left_neighbor;
 		          int child=_data[_minimum].child;
 		          int last_child=_data[child].left_neighbor;
 		          makeroot(child);
 		          _data[left].right_neighbor=child;
 		          _data[child].left_neighbor=left;
 		          _data[right].left_neighbor=last_child;
 		          _data[last_child].right_neighbor=right;
+		        }
 		        _minimum=right;
 		        balance();
 		      } // the case where there are more roots
 		      --_num;
+		    }
-		    /// \brief Deletes \c item from the heap.
+		    /// \brief Remove the given item from the heap.
 		    ///
 		    /// This method deletes \c item from the heap, if \c item was already
 		    /// stored in the heap. It is quite inefficient in Fibonacci heaps.
 		    /// This function removes the given item from the heap if it is
 		    /// already stored.
 		    /// \param item The item to delete.
 		    /// \pre \e item must be in the heap.
 		    void erase (const Item& item) {
 		      int i=_iim[item];
 		      if ( i >= 0 && _data[i].in ) {
 		        if ( _data[i].parent!=-1 ) {
 		          int p=_data[i].parent;
 		          cut(i,p);
 		          cascade(p);
+		        }
 		        _minimum=i;     //As if its prio would be -infinity
 		        pop();
+		      }
+		    }
-		    /// \brief Decreases the priority of \c item to \c value.
+		    /// \brief The priority of the given item.
 		    ///
 		    /// This method decreases the priority of \c item to \c value.
 		    /// \pre \c item must be stored in the heap with priority at least \c
 		    ///   value relative to \c Compare.
 		    void decrease (Item item, const Prio& value) {
 		    /// This function returns the priority of the given item.
 		    /// \param item The item.
 		    /// \pre \e item must be in the heap.
 		    Prio operator[](const Item& item) const {
 		      return _data[_iim[item]].prio;
+		    }
 		    /// \brief Set the priority of an item or insert it, if it is
 		    /// not stored in the heap.
 		    ///
 		    /// This method sets the priority of the given item if it is
 		    /// already stored in the heap. Otherwise it inserts the given
 		    /// item into the heap with the given priority.
 		    /// \param item The item.
 		    /// \param prio The priority.
 		    void set (const Item& item, const Prio& prio) {
 		      int i=_iim[item];
-		      _data[i].prio=value;
+		      if ( i >= 0 && _data[i].in ) {
 		        if ( _comp(prio, _data[i].prio) ) decrease(item, prio);
 		        if ( _comp(_data[i].prio, prio) ) increase(item, prio);
 		      } else push(item, prio);
+		    }
 		    /// \brief Decrease the priority of an item to the given value.
 		    ///
 		    /// This function decreases the priority of an item to the given value.
 		    /// \param item The item.
 		    /// \param prio The priority.
 		    /// \pre \e item must be stored in the heap with priority at least \e prio.
 		    void decrease (const Item& item, const Prio& prio) {
 		      int i=_iim[item];
 		      _data[i].prio=prio;
 		      int p=_data[i].parent;
-		      if ( p!=-1 && _comp(value, _data[p].prio) ) {
+		      if ( p!=-1 && _comp(prio, _data[p].prio) ) {
 		        cut(i,p);
 		        cascade(p);
+		      }
-		      if ( _comp(value, _data[_minimum].prio) ) _minimum=i;
+		      if ( _comp(prio, _data[_minimum].prio) ) _minimum=i;
+		    }
-		    /// \brief Increases the priority of \c item to \c value.
+		    /// \brief Increase the priority of an item to the given value.
 		    ///
 		    /// This method sets the priority of \c item to \c value. Though
 		    /// there is no precondition on the priority of \c item, this
 		    /// method should be used only if it is indeed necessary to increase
 		    /// (relative to \c Compare) the priority of \c item, because this
 		    /// method is inefficient.
 		    void increase (Item item, const Prio& value) {
 		    /// This function increases the priority of an item to the given value.
 		    /// \param item The item.
 		    /// \param prio The priority.
 		    /// \pre \e item must be stored in the heap with priority at most \e prio.
 		    void increase (const Item& item, const Prio& prio) {
 		      erase(item);
-		      push(item, value);
+		      push(item, prio);
+		    }
 		    /// \brief Returns if \c item is in, has already been in, or has never
-		    /// been in the heap.
+		    /// \brief Return the state of an item.
 		    ///
 		    /// 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.
 		    /// This method returns \c PRE_HEAP if the given item has never
 		    /// been in the heap, \c IN_HEAP if it is in the heap at the moment,
 		    /// and \c POST_HEAP otherwise.
 		    /// In the latter case it is possible that the item will get back
 		    /// to the heap again.
 		    /// \param item The item.
 		    State state(const Item &item) const {
 		      int i=_iim[item];
 		      if( i>=0 ) {
 		        if ( _data[i].in ) i=0;
 		        else i=-2;
+		      }
 		      return State(i);
+		    }
-		    /// \brief Sets the state of the \c item in the heap.
+		    /// \brief Set the state of an item in the heap.
 		    ///
 		    /// Sets the state of the \c item in the heap. It can be used to
 		    /// manually clear the heap when it is important to achive the
-		    /// better time _complexity.
+		    /// This function sets the state of the given item in the heap.
 		    /// It can be used to manually clear the heap when it is important
 		    /// to achive better time complexity.
 		    /// \param i The item.
 		    /// \param st The state. It should not be \c IN_HEAP.
 		    void state(const Item& i, State st) {
 		      switch (st) {
 		      case POST_HEAP:
 		      case PRE_HEAP:
 		        if (state(i) == IN_HEAP) {
 		          erase(i);
+		        }
 		        _iim[i] = st;
 		        break;
 		      case IN_HEAP:
 		        break;
+		      }
+		    }
 		  private:
 		    void balance() {
 		      int maxdeg=int( std::floor( 2.08*log(double(_data.size()))))+1;
 		      std::vector<int> A(maxdeg,-1);
 		      /*
 		       *Recall that now minimum does not point to the minimum prio element.
 		       *We set minimum to this during balance().
 		       */
 		      int anchor=_data[_minimum].left_neighbor;
 		      int next=_minimum;
 		      bool end=false;
 		      do {
 		        int active=next;
 		        if ( anchor==active ) end=true;
 		        int d=_data[active].degree;
 		        next=_data[active].right_neighbor;
 		        while (A[d]!=-1) {
 		          if( _comp(_data[active].prio, _data[A[d]].prio) ) {
 		            fuse(active,A[d]);
 		          } else {
 		            fuse(A[d],active);
 		            active=A[d];
+		          }
 		          A[d]=-1;
 		          ++d;
+		        }

lemon/radix_heap.h

Show inline comments

 		/* -*- mode: C++; indent-tabs-mode: nil; -*-
+		 *
 		 * This file is a part of LEMON, a generic C++ optimization library.
+		 *
 		 * Copyright (C) 2003-2009
 		 * 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_RADIX_HEAP_H
 		#define LEMON_RADIX_HEAP_H
 		///\ingroup auxdat
 		///\file
-		///\brief Radix Heap implementation.
+		///\brief Radix heap implementation.
 		#include <vector>
 		#include <lemon/error.h>
 		namespace lemon {
-		  /// \ingroup auxdata
+		  /// \ingroup auxdat
 		  ///
-		  /// \brief A Radix Heap implementation.
+		  /// \brief Radix heap data structure.
 		  ///
 		  /// This class implements the \e radix \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. This heap type can store only items with \e int priority.
 		  /// In a heap one can change the priority of an item, add or erase an
 		  /// item, but the priority cannot be decreased under the last removed
-		  /// item's priority.
+		  /// This class implements the \e radix \e heap data structure.
 		  /// It practically conforms to the \ref concepts::Heap "heap concept",
 		  /// but it has some limitations due its special implementation.
 		  /// The type of the priorities must be \c int and the priority of an
 		  /// item cannot be decreased under the priority of the last removed item.
 		  ///
 		  /// \param IM A read and writable Item int map, used internally
 		  /// to handle the cross references.
 		  ///
 		  /// \see BinHeap
-		  /// \see Dijkstra
+		  /// \tparam IM A read-writable item map with \c int values, used
 		  /// internally to handle the cross references.
 		  template <typename IM>
 		  class RadixHeap {
 		  public:
-		    typedef typename IM::Key Item;
 		    /// Type of the item-int map.
 		    typedef IM ItemIntMap;
 		    /// Type of the priorities.
 		    typedef int Prio;
-		    typedef IM ItemIntMap;
+		    /// Type of the items stored in the heap.
 		    typedef typename ItemIntMap::Key Item;
 		    /// \brief Exception thrown by RadixHeap.
 		    ///
 		    /// This Exception is thrown when a smaller priority
 		    /// is inserted into the \e RadixHeap then the last time erased.
 		    /// This exception is thrown when an item is inserted into a
 		    /// RadixHeap with a priority smaller than the last erased one.
 		    /// \see RadixHeap
 		    class UnderFlowPriorityError : public Exception {
 		    public:
 		      virtual const char* what() const throw() {
 		        return "lemon::RadixHeap::UnderFlowPriorityError";
+		      }
 		    };
-		    /// \brief Type to represent the items states.
+		    /// \brief Type to represent the states of the items.
 		    ///
 		    /// 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
 		    /// Each item has a state associated to it. It can 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...
 		    /// The item-int map must be initialized in such way that it assigns
 		    /// \c PRE_HEAP (<tt>-1</tt>) to any element to be put in the heap.
 		    enum State {
 		      IN_HEAP = 0,
 		      PRE_HEAP = -1,
-		      POST_HEAP = -2
+		      IN_HEAP = 0,    ///< = 0.
 		      PRE_HEAP = -1,  ///< = -1.
 		      POST_HEAP = -2  ///< = -2.
 		    };
 		  private:
 		    struct RadixItem {
 		      int prev, next, box;
 		      Item item;
 		      int prio;
 		      RadixItem(Item _item, int _prio) : item(_item), prio(_prio) {}
 		    };
 		    struct RadixBox {
 		      int first;
 		      int min, size;
 		      RadixBox(int _min, int _size) : first(-1), min(_min), size(_size) {}
 		    };
 		    std::vector<RadixItem> data;
 		    std::vector<RadixBox> boxes;
 		    ItemIntMap &_iim;
 		  public:
 		  public:
 		    /// \brief The constructor.
 		    /// \brief Constructor.
 		    ///
 		    /// The constructor.
 		    ///
 		    /// \param map It 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 minimal The initial minimal value of the heap.
 		    /// \param capacity It determines the initial capacity of the heap.
 		    RadixHeap(ItemIntMap &map, int minimal = 0, int capacity = 0)
 		      : _iim(map) {
 		      boxes.push_back(RadixBox(minimal, 1));
 		      boxes.push_back(RadixBox(minimal + 1, 1));
-		      while (lower(boxes.size() - 1, capacity + minimal - 1)) {
+		    /// Constructor.
 		    /// \param map A map that assigns \c int values to the items.
 		    /// It is used internally to handle the cross references.
 		    /// The assigned value must be \c PRE_HEAP (<tt>-1</tt>) for each item.
 		    /// \param minimum The initial minimum value of the heap.
 		    /// \param capacity The initial capacity of the heap.
 		    RadixHeap(ItemIntMap &map, int minimum = 0, int capacity = 0)
 		      : _iim(map)
+		    {
 		      boxes.push_back(RadixBox(minimum, 1));
 		      boxes.push_back(RadixBox(minimum + 1, 1));
 		      while (lower(boxes.size() - 1, capacity + minimum - 1)) {
 		        extend();
+		      }
+		    }
 		    /// The number of items stored in the heap.
+		    /// \brief The number of items stored in the heap.
 		    ///
-		    /// \brief Returns the number of items stored in the heap.
+		    /// This function returns the number of items stored in the heap.
 		    int size() const { return data.size(); }
-		    /// \brief Checks if the heap stores no items.
 		    /// \brief Check if the heap is empty.
 		    ///
-		    /// Returns \c true if and only if the heap stores no items.
+		    /// This function returns \c true if the heap is empty.
 		    bool empty() const { return data.empty(); }
-		    /// \brief Make empty this heap.
+		    /// \brief Make the heap empty.
 		    ///
 		    /// Make empty this heap. It does not change the cross reference
 		    /// map.  If you want to reuse a heap what is not surely empty you
 		    /// should first clear the heap and after that you should set the
 		    /// cross reference map for each item to \c PRE_HEAP.
-		    void clear(int minimal = 0, int capacity = 0) {
+		    /// This functon makes the heap empty.
 		    /// It does not change the cross reference map. If you want to reuse
 		    /// a heap that is not surely empty, you should first clear it and
 		    /// then you should set the cross reference map to \c PRE_HEAP
 		    /// for each item.
 		    /// \param minimum The minimum value of the heap.
 		    /// \param capacity The capacity of the heap.
 		    void clear(int minimum = 0, int capacity = 0) {
 		      data.clear(); boxes.clear();
 		      boxes.push_back(RadixBox(minimal, 1));
 		      boxes.push_back(RadixBox(minimal + 1, 1));
-		      while (lower(boxes.size() - 1, capacity + minimal - 1)) {
+		      boxes.push_back(RadixBox(minimum, 1));
 		      boxes.push_back(RadixBox(minimum + 1, 1));
 		      while (lower(boxes.size() - 1, capacity + minimum - 1)) {
 		        extend();
+		      }
+		    }
 		  private:
 		    bool upper(int box, Prio pr) {
 		      return pr < boxes[box].min;
+		    }
 		    bool lower(int box, Prio pr) {
 		      return pr >= boxes[box].min + boxes[box].size;
+		    }
-		    /// \brief Remove item from the box list.
 		    // Remove item from the box list
 		    void remove(int index) {
 		      if (data[index].prev >= 0) {
 		        data[data[index].prev].next = data[index].next;
 		      } else {
 		        boxes[data[index].box].first = data[index].next;
+		      }
 		      if (data[index].next >= 0) {
 		        data[data[index].next].prev = data[index].prev;
+		      }
+		    }
-		    /// \brief Insert item into the box list.
 		    // Insert item into the box list
 		    void insert(int box, int index) {
 		      if (boxes[box].first == -1) {
 		        boxes[box].first = index;
 		        data[index].next = data[index].prev = -1;
 		      } else {
 		        data[index].next = boxes[box].first;
 		        data[boxes[box].first].prev = index;
 		        data[index].prev = -1;
 		        boxes[box].first = index;
+		      }
 		      data[index].box = box;
+		    }
-		    /// \brief Add a new box to the box list.
 		    // Add a new box to the box list
 		    void extend() {
 		      int min = boxes.back().min + boxes.back().size;
 		      int bs = 2 * boxes.back().size;
 		      boxes.push_back(RadixBox(min, bs));
+		    }
-		    /// \brief Move an item up into the proper box.
 		    // Move an item up into the proper box.
 		    void bubble_up(int index) {
 		      if (!lower(data[index].box, data[index].prio)) return;
 		      remove(index);
 		      int box = findUp(data[index].box, data[index].prio);
 		      insert(box, index);
+		    }
-		    /// \brief Find up the proper box for the item with the given prio.
+		    // Find up the proper box for the item with the given priority
 		    int findUp(int start, int pr) {
 		      while (lower(start, pr)) {
 		        if (++start == int(boxes.size())) {
 		          extend();
+		        }
+		      }
 		      return start;
+		    }
-		    /// \brief Move an item down into the proper box.
 		    // Move an item down into the proper box
 		    void bubble_down(int index) {
 		      if (!upper(data[index].box, data[index].prio)) return;
 		      remove(index);
 		      int box = findDown(data[index].box, data[index].prio);
 		      insert(box, index);
+		    }
-		    /// \brief Find up the proper box for the item with the given prio.
+		    // Find down the proper box for the item with the given priority
 		    int findDown(int start, int pr) {
 		      while (upper(start, pr)) {
 		        if (--start < 0) throw UnderFlowPriorityError();
+		      }
 		      return start;
+		    }
-		    /// \brief Find the first not empty box.
+		    // Find the first non-empty box
 		    int findFirst() {
 		      int first = 0;
 		      while (boxes[first].first == -1) ++first;
 		      return first;
+		    }
-		    /// \brief Gives back the minimal prio of the box.
+		    // Gives back the minimum priority of the given box
 		    int minValue(int box) {
 		      int min = data[boxes[box].first].prio;
 		      for (int k = boxes[box].first; k != -1; k = data[k].next) {
 		        if (data[k].prio < min) min = data[k].prio;
+		      }
 		      return min;
+		    }
 		    /// \brief Rearrange the items of the heap and makes the
 		    /// first box not empty.
 		    // Rearrange the items of the heap and make the first box non-empty
 		    void moveDown() {
 		      int box = findFirst();
 		      if (box == 0) return;
 		      int min = minValue(box);
 		      for (int i = 0; i <= box; ++i) {
 		        boxes[i].min = min;
 		        min += boxes[i].size;
+		      }
 		      int curr = boxes[box].first, next;
 		      while (curr != -1) {
 		        next = data[curr].next;
 		        bubble_down(curr);
 		        curr = next;
+		      }
+		    }
 		    void relocate_last(int index) {
 		      if (index != int(data.size()) - 1) {
 		        data[index] = data.back();
 		        if (data[index].prev != -1) {
 		          data[data[index].prev].next = index;
 		        } else {
 		          boxes[data[index].box].first = index;
+		        }
 		        if (data[index].next != -1) {
 		          data[data[index].next].prev = index;
+		        }
 		        _iim[data[index].item] = index;
+		      }
 		      data.pop_back();
+		    }
 		  public:
 		    /// \brief Insert an item into the heap with the given priority.
 		    ///
-		    /// Adds \c i to the heap with priority \c p.
+		    /// This function inserts the given item into the heap with the
 		    /// given priority.
 		    /// \param i The item to insert.
 		    /// \param p The priority of the item.
 		    /// \pre \e i must not be stored in the heap.
 		    /// \warning This method may throw an \c UnderFlowPriorityException.
 		    void push(const Item &i, const Prio &p) {
 		      int n = data.size();
 		      _iim.set(i, n);
 		      data.push_back(RadixItem(i, p));
 		      while (lower(boxes.size() - 1, p)) {
 		        extend();
+		      }
 		      int box = findDown(boxes.size() - 1, p);
 		      insert(box, n);
+		    }
-		    /// \brief Returns the item with minimum priority.
+		    /// \brief Return the item having minimum priority.
 		    ///
 		    /// This method returns the item with minimum priority.
 		    /// \pre The heap must be nonempty.
 		    /// This function returns the item having minimum priority.
 		    /// \pre The heap must be non-empty.
 		    Item top() const {
 		      const_cast<RadixHeap<ItemIntMap>&>(*this).moveDown();
 		      return data[boxes[0].first].item;
+		    }
-		    /// \brief Returns the minimum priority.
+		    /// \brief The minimum priority.
 		    ///
 		    /// It returns the minimum priority.
 		    /// \pre The heap must be nonempty.
 		    /// This function returns the minimum priority.
 		    /// \pre The heap must be non-empty.
 		    Prio prio() const {
 		      const_cast<RadixHeap<ItemIntMap>&>(*this).moveDown();
 		      return data[boxes[0].first].prio;
+		     }
-		    /// \brief Deletes the item with minimum priority.
+		    /// \brief Remove the item having minimum priority.
 		    ///
-		    /// This method deletes the item with minimum priority.
+		    /// This function removes the item having minimum priority.
 		    /// \pre The heap must be non-empty.
 		    void pop() {
 		      moveDown();
 		      int index = boxes[0].first;
 		      _iim[data[index].item] = POST_HEAP;
 		      remove(index);
 		      relocate_last(index);
+		    }
-		    /// \brief Deletes \c i from the heap.
+		    /// \brief Remove the given item 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.
+		    /// This function removes the given item from the heap if it is
 		    /// already stored.
 		    /// \param i The item to delete.
 		    /// \pre \e i must be in the heap.
 		    void erase(const Item &i) {
 		      int index = _iim[i];
 		      _iim[i] = POST_HEAP;
 		      remove(index);
 		      relocate_last(index);
+		   }
-		    /// \brief Returns the priority of \c i.
+		    /// \brief The priority of the given item.
 		    ///
 		    /// This function returns the priority of item \c i.
 		    /// \pre \c i must be in the heap.
 		    /// This function returns the priority of the given item.
 		    /// \param i The item.
 		    /// \pre \e i must be in the heap.
 		    Prio operator[](const Item &i) const {
 		      int idx = _iim[i];
 		      return data[idx].prio;
+		    }
 		    /// \brief \c i gets to the heap with priority \c p independently
 		    /// if \c i was already there.
 		    /// \brief Set the priority of an item or insert it, if it is
 		    /// not stored in the heap.
 		    ///
 		    /// 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.
-		    /// It may throw an \e UnderFlowPriorityException.
+		    /// This method sets the priority of the given item if it is
 		    /// already stored in the heap. Otherwise it inserts the given
 		    /// item into the heap with the given priority.
 		    /// \param i The item.
 		    /// \param p The priority.
 		    /// \pre \e i must be in the heap.
 		    /// \warning This method may throw an \c UnderFlowPriorityException.
 		    void set(const Item &i, const Prio &p) {
 		      int idx = _iim[i];
 		      if( idx < 0 ) {
 		        push(i, p);
+		      }
 		      else if( p >= data[idx].prio ) {
 		        data[idx].prio = p;
 		        bubble_up(idx);
 		      } else {
 		        data[idx].prio = p;
 		        bubble_down(idx);
+		      }
+		    }
 		    /// \brief Decreases the priority of \c i to \c p.
 		    /// \brief Decrease the priority of an item to the given value.
 		    ///
 		    /// 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, and
-		    /// \c should be greater or equal to the last removed item's priority.
+		    /// This function decreases the priority of an item to the given value.
 		    /// \param i The item.
 		    /// \param p The priority.
 		    /// \pre \e i must be stored in the heap with priority at least \e p.
 		    /// \warning This method may throw an \c UnderFlowPriorityException.
 		    void decrease(const Item &i, const Prio &p) {
 		      int idx = _iim[i];
 		      data[idx].prio = p;
 		      bubble_down(idx);
+		    }
-		    /// \brief Increases the priority of \c i to \c p.
+		    /// \brief Increase the priority of an item to the given value.
 		    ///
 		    /// 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
 		    /// This function increases the priority of an item to the given value.
 		    /// \param i The item.
 		    /// \param p The priority.
 		    /// \pre \e i must be stored in the heap with priority at most \e p.
 		    void increase(const Item &i, const Prio &p) {
 		      int idx = _iim[i];
 		      data[idx].prio = p;
 		      bubble_up(idx);
+		    }
 		    /// \brief Returns if \c item is in, has already been in, or has
 		    /// never been in the heap.
 		    /// \brief Return the state of an item.
 		    ///
 		    /// 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.
 		    /// This method returns \c PRE_HEAP if the given item has never
 		    /// been in the heap, \c IN_HEAP if it is in the heap at the moment,
 		    /// and \c POST_HEAP otherwise.
 		    /// In the latter case it is possible that the item will get back
 		    /// to the heap again.
 		    /// \param i The item.
 		    State state(const Item &i) const {
 		      int s = _iim[i];
 		      if( s >= 0 ) s = 0;
 		      return State(s);
+		    }
-		    /// \brief Sets the state of the \c item in the heap.
+		    /// \brief Set the state of an item in the heap.
 		    ///
 		    /// Sets the state of the \c item in the heap. It can be used to
 		    /// manually clear the heap when it is important to achive the
-		    /// better time complexity.
+		    /// This function sets the state of the given item in the heap.
 		    /// It can be used to manually clear the heap when it is important
 		    /// to achive better time complexity.
 		    /// \param i The item.
 		    /// \param st The state. It should not be \c IN_HEAP.
 		    void state(const Item& i, State st) {
 		      switch (st) {
 		      case POST_HEAP:
 		      case PRE_HEAP:
 		        if (state(i) == IN_HEAP) {
 		          erase(i);
+		        }
 		        _iim[i] = st;
 		        break;
 		      case IN_HEAP:
 		        break;
+		      }
+		    }
 		  }; // class RadixHeap
 		} // namespace lemon
 		#endif // LEMON_RADIX_HEAP_H

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