LEMON/LEMON-main Changeset - r683:9f529abcaebf

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Changeset - r683:9f529abcaebf

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r683:9f529abcaebf

Thu, 11 Jun 2009 23:13:24

[Not Reviewed]

0 comments (0 inline)

deba@inf.elte.hu
deba@inf.elte.hu

Unification of names in heaps (#50)

0 4 0

default

4 files changed with 297 insertions and 294 deletions:

lemon/bin_heap.h

lemon/bucket_heap.h

129

127

lemon/fib_heap.h

143

142

lemon/radix_heap.h

↑ Collapse diff ↑

lemon/bin_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_BIN_HEAP_H
 		#define LEMON_BIN_HEAP_H
 		///\ingroup auxdat
 		///\file
 		///\brief Binary Heap implementation.
 		#include <vector>
 		#include <utility>
 		#include <functional>
 		namespace lemon {
 		  ///\ingroup auxdat
 		  ///
 		  ///\brief A Binary Heap implementation.
 		  ///
 		  ///This class implements the \e binary \e heap data structure.
 		  ///
 		  ///This class implements the \e binary \e heap data structure.
 		  ///
 		  ///A \e heap is a data structure for storing items with specified values
 		  ///called \e priorities in such a way that finding the item with minimum
-		  ///priority is efficient. \c Comp specifies the ordering of the priorities.
+		  ///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 Comp A functor class for the ordering of the priorities.
+		  ///\tparam CMP A functor class for the ordering of the priorities.
 		  ///The default is \c std::less<PR>.
 		  ///
 		  ///\sa FibHeap
 		  ///\sa Dijkstra
-		  template <typename PR, typename IM, typename Comp = std::less<PR> >
+		  template <typename PR, typename IM, typename CMP = std::less<PR> >
 		  class BinHeap {
 		  public:
 		    ///\e
 		    typedef IM ItemIntMap;
 		    ///\e
 		    typedef PR Prio;
 		    ///\e
 		    typedef typename ItemIntMap::Key Item;
 		    ///\e
 		    typedef std::pair<Item,Prio> Pair;
 		    ///\e
-		    typedef Comp Compare;
+		    typedef CMP Compare;
 		    /// \brief Type to represent the items states.
 		    ///
 		    /// Each Item element have a state associated to it. It may be "in heap",
 		    /// "pre heap" or "post heap". The latter two are indifferent from the
 		    /// heap's point of view, but may be useful to the user.
 		    ///
 		    /// The 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.
 		    ///
 		    /// 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.
 		    explicit BinHeap(ItemIntMap &map) : _iim(map) {}
 		    /// \brief The 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.
 		    BinHeap(ItemIntMap &map, const Compare &comp)
 		      : _iim(map), _comp(comp) {}
 		    /// The number of items stored in the heap.
 		    ///
 		    /// \brief Returns the number of items stored in the heap.
 		    int size() const { return _data.size(); }
 		    /// \brief Checks if the heap stores no items.
 		    ///
 		    /// Returns \c true if and only if the heap stores no items.
 		    bool empty() const { return _data.empty(); }
 		    /// \brief Make empty this heap.
 		    ///
 		    /// 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.
 		    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;

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.
 		#include <vector>
 		#include <utility>
 		#include <functional>
 		namespace lemon {
 		  namespace _bucket_heap_bits {
-		    template <bool minimize>
+		    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.
 		  ///
 		  /// 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.
 		  ///
-		  /// \param _ItemIntMap A read and writable Item int map, used internally
+		  /// \param IM A read and write Item int map, used internally
 		  /// to handle the cross references.
 		  /// \param minimize If the given parameter is true then the heap gives back
 		  /// the lowest priority.
-		  template <typename _ItemIntMap, bool minimize = true>
+		  /// \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.
 		  template <typename IM, bool MIN = true>
 		  class BucketHeap {
 		  public:
 		    /// \e
-		    typedef typename _ItemIntMap::Key Item;
+		    typedef typename IM::Key Item;
 		    /// \e
 		    typedef int Prio;
 		    /// \e
 		    typedef std::pair<Item, Prio> Pair;
 		    /// \e
-		    typedef _ItemIntMap ItemIntMap;
+		    typedef IM ItemIntMap;
 		  private:
-		    typedef _bucket_heap_bits::DirectionTraits<minimize> Direction;
+		    typedef _bucket_heap_bits::DirectionTraits<MIN> Direction;
 		  public:
 		    /// \brief Type to represent the items states.
 		    ///
 		    /// Each Item element have a state associated to it. It may be "in heap",
 		    /// "pre heap" or "post heap". The latter two are indifferent from the
 		    /// heap's point of view, but may be useful to the user.
 		    ///
 		    /// The ItemIntMap \e should be initialized in such way that it maps
 		    /// PRE_HEAP (-1) to any element to be put in the heap...
 		    /// 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.
 		    };
 		  public:
 		    /// \brief The constructor.
 		    ///
 		    /// The constructor.
-		    /// \param _index should be given to the constructor, since it is used
+		    /// \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.
-		    explicit BucketHeap(ItemIntMap &_index) : index(_index), minimal(0) {}
+		    explicit BucketHeap(ItemIntMap &map) : _iim(map), _minimum(0) {}
 		    /// The number of items stored in the heap.
 		    ///
 		    /// \brief Returns the number of items stored in the heap.
-		    int size() const { return data.size(); }
+		    int size() const { return _data.size(); }
 		    /// \brief Checks if the heap stores no items.
 		    ///
 		    /// Returns \c true if and only if the heap stores no items.
-		    bool empty() const { return data.empty(); }
+		    bool empty() const { return _data.empty(); }
 		    /// \brief Make empty this heap.
 		    ///
 		    /// 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() {
-		      data.clear(); first.clear(); minimal = 0;
+		      _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;
 		      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;
+		          _first[_data[idx].value] = idx;
+		        }
 		        if (data[idx].next != -1) {
 		          data[data[idx].next].prev = idx;
 		        if (_data[idx].next != -1) {
 		          _data[_data[idx].next].prev = idx;
+		        }
-		        index[data[idx].item] = idx;
+		        _iim[_data[idx].item] = idx;
+		      }
-		      data.pop_back();
+		      _data.pop_back();
+		    }
 		    void unlace(int idx) {
 		      if (data[idx].prev != -1) {
 		        data[data[idx].prev].next = data[idx].next;
 		      if (_data[idx].prev != -1) {
 		        _data[_data[idx].prev].next = _data[idx].next;
 		      } else {
-		        first[data[idx].value] = data[idx].next;
+		        _first[_data[idx].value] = _data[idx].next;
+		      }
 		      if (data[idx].next != -1) {
 		        data[data[idx].next].prev = data[idx].prev;
 		      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);
 		      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;
+		      _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;
 		      _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.
 		    /// \param p The pair to insert.
 		    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.
 		    /// \param i The item to insert.
 		    /// \param p The priority of the item.
 		    void push(const Item &i, const Prio &p) {
 		      int idx = data.size();
 		      index[i] = idx;
-		      data.push_back(BucketItem(i, p));
+		      int idx = _data.size();
 		      _iim[i] = idx;
 		      _data.push_back(BucketItem(i, p));
 		      lace(idx);
 		      if (Direction::less(p, minimal)) {
 		        minimal = p;
 		      if (Direction::less(p, _minimum)) {
 		        _minimum = p;
+		      }
+		    }
 		    /// \brief Returns the item with minimum priority.
 		    ///
 		    /// This method returns the item with minimum priority.
 		    /// \pre The heap must be nonempty.
 		    Item top() const {
 		      while (first[minimal] == -1) {
 		        Direction::increase(minimal);
 		      while (_first[_minimum] == -1) {
 		        Direction::increase(_minimum);
+		      }
-		      return data[first[minimal]].item;
+		      return _data[_first[_minimum]].item;
+		    }
 		    /// \brief Returns the minimum priority.
 		    ///
 		    /// It returns the minimum priority.
 		    /// \pre The heap must be nonempty.
 		    Prio prio() const {
 		      while (first[minimal] == -1) {
 		        Direction::increase(minimal);
 		      while (_first[_minimum] == -1) {
 		        Direction::increase(_minimum);
+		      }
-		      return minimal;
+		      return _minimum;
+		    }
 		    /// \brief Deletes the item with minimum priority.
 		    ///
 		    /// This method deletes the item with minimum priority from the heap.
 		    /// \pre The heap must be non-empty.
 		    void pop() {
 		      while (first[minimal] == -1) {
 		        Direction::increase(minimal);
 		      while (_first[_minimum] == -1) {
 		        Direction::increase(_minimum);
+		      }
 		      int idx = first[minimal];
 		      index[data[idx].item] = -2;
 		      int idx = _first[_minimum];
 		      _iim[_data[idx].item] = -2;
 		      unlace(idx);
 		      relocate_last(idx);
+		    }
 		    /// \brief Deletes \c i from the heap.
 		    ///
 		    /// This method deletes item \c i from the heap, if \c i was
 		    /// already stored in the heap.
 		    /// \param i The item to erase.
 		    void erase(const Item &i) {
 		      int idx = index[i];
 		      index[data[idx].item] = -2;
 		      int idx = _iim[i];
 		      _iim[_data[idx].item] = -2;
 		      unlace(idx);
 		      relocate_last(idx);
+		    }
 		    /// \brief Returns the priority of \c i.
 		    ///
 		    /// This function returns the priority of item \c i.
 		    /// \pre \c i must be in the heap.
 		    /// \param i The item.
 		    Prio operator[](const Item &i) const {
 		      int idx = index[i];
 		      return data[idx].value;
 		      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.
 		    ///
 		    /// This method calls \ref push(\c i, \c p) if \c i is not stored
 		    /// in the heap and sets the priority of \c i to \c p otherwise.
 		    /// \param i The item.
 		    /// \param p The priority.
 		    void set(const Item &i, const Prio &p) {
-		      int idx = index[i];
+		      int idx = _iim[i];
 		      if (idx < 0) {
 		        push(i, p);
-		      } else if (Direction::less(p, data[idx].value)) {
+		      } 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.
 		    ///
 		    /// This method decreases the priority of item \c i to \c p.
 		    /// \pre \c i must be stored in the heap with priority at least \c
 		    /// p relative to \c Compare.
 		    /// \param i The item.
 		    /// \param p The priority.
 		    void decrease(const Item &i, const Prio &p) {
-		      int idx = index[i];
+		      int idx = _iim[i];
 		      unlace(idx);
 		      data[idx].value = p;
 		      if (Direction::less(p, minimal)) {
-		        minimal = p;
+		      _data[idx].value = p;
 		      if (Direction::less(p, _minimum)) {
 		        _minimum = p;
+		      }
 		      lace(idx);
+		    }
 		    /// \brief Increases the priority of \c i to \c p.
 		    ///
 		    /// This method sets the priority of item \c i to \c p.
 		    /// \pre \c i must be stored in the heap with priority at most \c
 		    /// p relative to \c Compare.
 		    /// \param i The item.
 		    /// \param p The priority.
 		    void increase(const Item &i, const Prio &p) {
-		      int idx = index[i];
+		      int idx = _iim[i];
 		      unlace(idx);
-		      data[idx].value = p;
+		      _data[idx].value = p;
 		      lace(idx);
+		    }
 		    /// \brief Returns if \c item is in, has already been in, or has
 		    /// never been in the heap.
 		    ///
 		    /// This method returns PRE_HEAP if \c item has never been in the
 		    /// heap, IN_HEAP if it is in the heap at the moment, and POST_HEAP
 		    /// otherwise. In the latter case it is possible that \c item will
 		    /// get back to the heap again.
 		    /// \param i The item.
 		    State state(const Item &i) const {
-		      int idx = index[i];
+		      int idx = _iim[i];
 		      if (idx >= 0) idx = 0;
 		      return State(idx);
+		    }
 		    /// \brief Sets the state of the \c 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.
 		    /// \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);
+		        }
-		        index[i] = st;
+		        _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& index;
 		    std::vector<int> first;
 		    std::vector<BucketItem> data;
 		    mutable int minimal;
 		    ItemIntMap& _iim;
 		    std::vector<int> _first;
 		    std::vector<BucketItem> _data;
 		    mutable int _minimum;
 		  }; // class BucketHeap
 		  /// \ingroup auxdat
 		  ///
 		  /// \brief A Simplified Bucket Heap implementation.
 		  ///
 		  /// 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.
 		  ///
-		  /// \param _ItemIntMap A read and writable Item int map, used internally
+		  /// \param IM A read and write Item int map, used internally
 		  /// to handle the cross references.
 		  /// \param minimize If the given parameter is true then the heap gives back
 		  /// the lowest priority.
 		  /// \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.
 		  ///
 		  /// \sa BucketHeap
-		  template <typename _ItemIntMap, bool minimize = true >
+		  template <typename IM, bool MIN = true >
 		  class SimpleBucketHeap {
 		  public:
-		    typedef typename _ItemIntMap::Key Item;
+		    typedef typename IM::Key Item;
 		    typedef int Prio;
 		    typedef std::pair<Item, Prio> Pair;
-		    typedef _ItemIntMap ItemIntMap;
+		    typedef IM ItemIntMap;
 		  private:
-		    typedef _bucket_heap_bits::DirectionTraits<minimize> Direction;
+		    typedef _bucket_heap_bits::DirectionTraits<MIN> Direction;
 		  public:
 		    /// \brief Type to represent the items states.
 		    ///
 		    /// Each Item element have a state associated to it. It may be "in heap",
 		    /// "pre heap" or "post heap". The latter two are indifferent from the
 		    /// heap's point of view, but may be useful to the user.
 		    ///
 		    /// The ItemIntMap \e should be initialized in such way that it maps
 		    /// PRE_HEAP (-1) to any element to be put in the heap...
 		    /// 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.
 		    };
 		  public:
 		    /// \brief The constructor.
 		    ///
 		    /// The constructor.
-		    /// \param _index should be given to the constructor, since it is used
+		    /// \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.
 		    explicit SimpleBucketHeap(ItemIntMap &_index)
 		      : index(_index), free(-1), num(0), minimal(0) {}
 		    explicit SimpleBucketHeap(ItemIntMap &map)
 		      : _iim(map), _free(-1), _num(0), _minimum(0) {}
 		    /// \brief Returns the number of items stored in the heap.
 		    ///
 		    /// The number of items stored in the heap.
-		    int size() const { return num; }
+		    int size() const { return _num; }
 		    /// \brief Checks if the heap stores no items.
 		    ///
 		    /// Returns \c true if and only if the heap stores no items.
-		    bool empty() const { return num == 0; }
+		    bool empty() const { return _num == 0; }
 		    /// \brief Make empty this heap.
 		    ///
 		    /// 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() {
-		      data.clear(); first.clear(); free = -1; num = 0; minimal = 0;
+		      _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.
 		    /// \param p The pair to insert.
 		    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.
 		    /// \param i The item to insert.
 		    /// \param p The priority of the item.
 		    void push(const Item &i, const Prio &p) {
 		      int idx;
 		      if (free == -1) {
 		        idx = data.size();
-		        data.push_back(BucketItem(i));
+		      if (_free == -1) {
 		        idx = _data.size();
 		        _data.push_back(BucketItem(i));
 		      } else {
 		        idx = free;
 		        free = data[idx].next;
-		        data[idx].item = i;
+		        idx = _free;
 		        _free = _data[idx].next;
 		        _data[idx].item = i;
+		      }
 		      index[i] = idx;
 		      if (p >= int(first.size())) first.resize(p + 1, -1);
 		      data[idx].next = first[p];
 		      first[p] = idx;
 		      if (Direction::less(p, minimal)) {
 		        minimal = p;
 		      _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;
+		      ++_num;
+		    }
 		    /// \brief Returns the item with minimum priority.
 		    ///
 		    /// This method returns the item with minimum priority.
 		    /// \pre The heap must be nonempty.
 		    Item top() const {
 		      while (first[minimal] == -1) {
 		        Direction::increase(minimal);
 		      while (_first[_minimum] == -1) {
 		        Direction::increase(_minimum);
+		      }
-		      return data[first[minimal]].item;
+		      return _data[_first[_minimum]].item;
+		    }
 		    /// \brief Returns the minimum priority.
 		    ///
 		    /// It returns the minimum priority.
 		    /// \pre The heap must be nonempty.
 		    Prio prio() const {
 		      while (first[minimal] == -1) {
 		        Direction::increase(minimal);
 		      while (_first[_minimum] == -1) {
 		        Direction::increase(_minimum);
+		      }
-		      return minimal;
+		      return _minimum;
+		    }
 		    /// \brief Deletes the item with minimum priority.
 		    ///
 		    /// This method deletes the item with minimum priority from the heap.
 		    /// \pre The heap must be non-empty.
 		    void pop() {
 		      while (first[minimal] == -1) {
 		        Direction::increase(minimal);
 		      while (_first[_minimum] == -1) {
 		        Direction::increase(_minimum);
+		      }
 		      int idx = first[minimal];
 		      index[data[idx].item] = -2;
 		      first[minimal] = data[idx].next;
 		      data[idx].next = free;
 		      free = idx;
 		      --num;
 		      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.
 		    ///
 		    /// 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.
 		    /// \param i The item.
 		    Prio operator[](const Item &i) const {
 		      for (int k = 0; k < first.size(); ++k) {
 		        int idx = first[k];
 		      for (int k = 0; k < _first.size(); ++k) {
 		        int idx = _first[k];
 		        while (idx != -1) {
-		          if (data[idx].item == i) {
+		          if (_data[idx].item == i) {
 		            return k;
+		          }
-		          idx = data[idx].next;
+		          idx = _data[idx].next;
+		        }
+		      }
 		      return -1;
+		    }
 		    /// \brief Returns if \c item is in, has already been in, or has
 		    /// never been in the heap.
 		    ///
 		    /// This method returns PRE_HEAP if \c item has never been in the
 		    /// heap, IN_HEAP if it is in the heap at the moment, and POST_HEAP
 		    /// otherwise. In the latter case it is possible that \c item will
 		    /// get back to the heap again.
 		    /// \param i The item.
 		    State state(const Item &i) const {
-		      int idx = index[i];
+		      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& index;
 		    std::vector<int> first;
 		    std::vector<BucketItem> data;
 		    int free, num;
-		    mutable int minimal;
+		    ItemIntMap& _iim;
 		    std::vector<int> _first;
 		    std::vector<BucketItem> _data;
 		    int _free, _num;
 		    mutable int _minimum;
 		  }; // class SimpleBucketHeap
+		}
 		#endif

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.
 		#include <vector>
 		#include <functional>
 		#include <lemon/math.h>
 		namespace lemon {
 		  /// \ingroup auxdat
 		  ///
 		  ///\brief Fibonacci Heap.
 		  ///
 		  ///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 Compare specifies the ordering of the priorities. In a heap
+		  ///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.
 		  ///
 		  ///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".
 		  ///
 		  ///\param _Prio Type of the priority of the items.
 		  ///\param _ItemIntMap A read and writable Item int map, used internally
 		  ///\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 _Compare A class for the ordering of the priorities. The
 		  ///default is \c std::less<_Prio>.
 		  ///\param CMP A class for the ordering of the priorities. The
 		  ///default is \c std::less<PRIO>.
 		  ///
 		  ///\sa BinHeap
 		  ///\sa Dijkstra
 		#ifdef DOXYGEN
 		  template <typename _Prio,
 		            typename _ItemIntMap,
-		            typename _Compare>
+		  template <typename PRIO, typename IM, typename CMP>
 		#else
 		  template <typename _Prio,
 		            typename _ItemIntMap,
-		            typename _Compare = std::less<_Prio> >
+		  template <typename PRIO, typename IM, typename CMP = std::less<PRIO> >
 		#endif
 		  class FibHeap {
 		  public:
 		    ///\e
-		    typedef _ItemIntMap ItemIntMap;
+		    typedef IM ItemIntMap;
 		    ///\e
-		    typedef _Prio Prio;
+		    typedef PRIO Prio;
 		    ///\e
 		    typedef typename ItemIntMap::Key Item;
 		    ///\e
 		    typedef std::pair<Item,Prio> Pair;
 		    ///\e
-		    typedef _Compare Compare;
+		    typedef CMP Compare;
 		  private:
-		    class store;
+		    class Store;
 		    std::vector<store> container;
 		    int minimum;
 		    ItemIntMap &iimap;
 		    Compare comp;
-		    int num_items;
+		    std::vector<Store> _data;
 		    int _minimum;
 		    ItemIntMap &_iim;
 		    Compare _comp;
 		    int _num;
 		  public:
-		    ///Status of the nodes
 		    /// \brief Type to represent the items states.
 		    ///
 		    /// Each Item element have a state associated to it. It may be "in heap",
 		    /// "pre heap" or "post heap". The latter two are indifferent from the
 		    /// heap's point of view, but may be useful to the user.
 		    ///
 		    /// The 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 {
 		      ///The node is in the heap
 		      IN_HEAP = 0,
 		      ///The node has never been in the heap
 		      PRE_HEAP = -1,
 		      ///The node was in the heap but it got out of it
 		      POST_HEAP = -2
 		      IN_HEAP = 0,    ///< = 0.
 		      PRE_HEAP = -1,  ///< = -1.
 		      POST_HEAP = -2  ///< = -2.
 		    };
 		    /// \brief The constructor
 		    ///
-		    /// \c _iimap should be given to the constructor, since it is
+		    /// \c map should be given to the constructor, since it is
 		    ///   used internally to handle the cross references.
 		    explicit FibHeap(ItemIntMap &_iimap)
 		      : minimum(0), iimap(_iimap), num_items() {}
 		    explicit FibHeap(ItemIntMap &map)
 		      : _minimum(0), _iim(map), _num() {}
 		    /// \brief The constructor
 		    ///
 		    /// \c _iimap should be given to the constructor, since it is used
 		    /// internally to handle the cross references. \c _comp is an
 		    /// \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.
 		    FibHeap(ItemIntMap &_iimap, const Compare &_comp)
 		      : minimum(0), iimap(_iimap), comp(_comp), num_items() {}
 		    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.
-		    int size() const { return num_items; }
+		    int size() const { return _num; }
 		    /// \brief Checks if the heap stores no items.
 		    ///
 		    ///   Returns \c true if and only if the heap stores no items.
-		    bool empty() const { return num_items==0; }
+		    bool empty() const { return _num==0; }
 		    /// \brief Make empty this heap.
 		    ///
 		    /// 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() {
-		      container.clear(); minimum = 0; num_items = 0;
+		      _data.clear(); _minimum = 0; _num = 0;
+		    }
 		    /// \brief \c item gets to the heap with priority \c value independently
 		    /// if \c item was already there.
 		    ///
 		    /// 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=iimap[item];
 		      if ( i >= 0 && container[i].in ) {
 		        if ( comp(value, container[i].prio) ) decrease(item, value);
 		        if ( comp(container[i].prio, value) ) increase(item, 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) {
-		      int i=iimap[item];
+		      int i=_iim[item];
 		      if ( i < 0 ) {
 		        int s=container.size();
 		        iimap.set( item, s );
-		        store st;
+		        int s=_data.size();
 		        _iim.set( item, s );
 		        Store st;
 		        st.name=item;
-		        container.push_back(st);
+		        _data.push_back(st);
 		        i=s;
 		      } else {
 		        container[i].parent=container[i].child=-1;
 		        container[i].degree=0;
 		        container[i].in=true;
 		        container[i].marked=false;
 		        _data[i].parent=_data[i].child=-1;
 		        _data[i].degree=0;
 		        _data[i].in=true;
 		        _data[i].marked=false;
+		      }
 		      if ( num_items ) {
 		        container[container[minimum].right_neighbor].left_neighbor=i;
 		        container[i].right_neighbor=container[minimum].right_neighbor;
 		        container[minimum].right_neighbor=i;
 		        container[i].left_neighbor=minimum;
 		        if ( comp( value, container[minimum].prio) ) minimum=i;
 		      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;
 		      } else {
 		        container[i].right_neighbor=container[i].left_neighbor=i;
 		        minimum=i;
 		        _data[i].right_neighbor=_data[i].left_neighbor=i;
 		        _minimum=i;
+		      }
 		      container[i].prio=value;
 		      ++num_items;
 		      _data[i].prio=value;
 		      ++_num;
+		    }
 		    /// \brief Returns the item with minimum priority relative to \c Compare.
 		    ///
 		    /// This method returns the item with minimum priority relative to \c
 		    /// Compare.
 		    /// \pre The heap must be nonempty.
-		    Item top() const { return container[minimum].name; }
+		    Item top() const { return _data[_minimum].name; }
 		    /// \brief Returns the minimum priority relative to \c Compare.
 		    ///
 		    /// It returns the minimum priority relative to \c Compare.
 		    /// \pre The heap must be nonempty.
-		    const Prio& prio() const { return container[minimum].prio; }
+		    const Prio& prio() const { return _data[_minimum].prio; }
 		    /// \brief Returns the priority of \c item.
 		    ///
 		    /// It returns the priority of \c item.
 		    /// \pre \c item must be in the heap.
 		    const Prio& operator[](const Item& item) const {
-		      return container[iimap[item]].prio;
+		      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.
 		    /// \pre The heap must be non-empty.
 		    void pop() {
 		      /*The first case is that there are only one root.*/
 		      if ( container[minimum].left_neighbor==minimum ) {
 		        container[minimum].in=false;
 		        if ( container[minimum].degree!=0 ) {
 		          makeroot(container[minimum].child);
-		          minimum=container[minimum].child;
+		      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=container[minimum].right_neighbor;
 		        unlace(minimum);
 		        container[minimum].in=false;
 		        if ( container[minimum].degree > 0 ) {
 		          int left=container[minimum].left_neighbor;
 		          int child=container[minimum].child;
-		          int last_child=container[child].left_neighbor;
+		        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);
 		          container[left].right_neighbor=child;
 		          container[child].left_neighbor=left;
 		          container[right].left_neighbor=last_child;
 		          container[last_child].right_neighbor=right;
 		          _data[left].right_neighbor=child;
 		          _data[child].left_neighbor=left;
 		          _data[right].left_neighbor=last_child;
 		          _data[last_child].right_neighbor=right;
+		        }
-		        minimum=right;
+		        _minimum=right;
 		        balance();
 		      } // the case where there are more roots
-		      --num_items;
+		      --_num;
+		    }
 		    /// \brief Deletes \c 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.
 		    void erase (const Item& item) {
-		      int i=iimap[item];
+		      int i=_iim[item];
 		      if ( i >= 0 && container[i].in ) {
 		        if ( container[i].parent!=-1 ) {
-		          int p=container[i].parent;
+		      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
+		        _minimum=i;     //As if its prio would be -infinity
 		        pop();
+		      }
+		    }
 		    /// \brief Decreases the priority of \c item to \c value.
 		    ///
 		    /// 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) {
 		      int i=iimap[item];
 		      container[i].prio=value;
-		      int p=container[i].parent;
+		      int i=_iim[item];
 		      _data[i].prio=value;
 		      int p=_data[i].parent;
-		      if ( p!=-1 && comp(value, container[p].prio) ) {
+		      if ( p!=-1 && _comp(value, _data[p].prio) ) {
 		        cut(i,p);
 		        cascade(p);
+		      }
-		      if ( comp(value, container[minimum].prio) ) minimum=i;
+		      if ( _comp(value, _data[_minimum].prio) ) _minimum=i;
+		    }
 		    /// \brief Increases the priority of \c item to \c 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) {
 		      erase(item);
 		      push(item, value);
+		    }
 		    /// \brief Returns if \c item is in, has already been in, or has never
 		    /// been in the heap.
 		    ///
 		    /// This method returns PRE_HEAP if \c item has never been in the
 		    /// heap, IN_HEAP if it is in the heap at the moment, and POST_HEAP
 		    /// otherwise. In the latter case it is possible that \c item will
 		    /// get back to the heap again.
 		    State state(const Item &item) const {
-		      int i=iimap[item];
+		      int i=_iim[item];
 		      if( i>=0 ) {
-		        if ( container[i].in ) 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.
 		    ///
 		    /// 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.
+		    /// 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);
+		        }
-		        iimap[i] = st;
+		        _iim[i] = st;
 		        break;
 		      case IN_HEAP:
 		        break;
+		      }
+		    }
 		  private:
 		    void balance() {
-		      int maxdeg=int( std::floor( 2.08*log(double(container.size()))))+1;
+		      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=container[minimum].left_neighbor;
 		      int next=minimum;
 		      int anchor=_data[_minimum].left_neighbor;
 		      int next=_minimum;
 		      bool end=false;
 		      do {
 		        int active=next;
 		        if ( anchor==active ) end=true;
 		        int d=container[active].degree;
 		        next=container[active].right_neighbor;
 		        int d=_data[active].degree;
 		        next=_data[active].right_neighbor;
 		        while (A[d]!=-1) {
-		          if( comp(container[active].prio, container[A[d]].prio) ) {
+		          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;
+		        }
 		        A[d]=active;
 		      } while ( !end );
 		      while ( container[minimum].parent >=0 )
 		        minimum=container[minimum].parent;
 		      int s=minimum;
 		      int m=minimum;
 		      while ( _data[_minimum].parent >=0 )
 		        _minimum=_data[_minimum].parent;
 		      int s=_minimum;
 		      int m=_minimum;
 		      do {
 		        if ( comp(container[s].prio, container[minimum].prio) ) minimum=s;
 		        s=container[s].right_neighbor;
 		        if ( _comp(_data[s].prio, _data[_minimum].prio) ) _minimum=s;
 		        s=_data[s].right_neighbor;
 		      } while ( s != m );
+		    }
 		    void makeroot(int c) {
 		      int s=c;
 		      do {
 		        container[s].parent=-1;
 		        s=container[s].right_neighbor;
 		        _data[s].parent=-1;
 		        s=_data[s].right_neighbor;
 		      } while ( s != c );
+		    }
 		    void cut(int a, int b) {
 		      /*
 		       *Replacing a from the children of b.
 		       */
-		      --container[b].degree;
+		      --_data[b].degree;
 		      if ( container[b].degree !=0 ) {
 		        int child=container[b].child;
 		      if ( _data[b].degree !=0 ) {
 		        int child=_data[b].child;
 		        if ( child==a )
-		          container[b].child=container[child].right_neighbor;
+		          _data[b].child=_data[child].right_neighbor;
 		        unlace(a);
+		      }
 		      /*Lacing a to the roots.*/
 		      int right=container[minimum].right_neighbor;
 		      container[minimum].right_neighbor=a;
 		      container[a].left_neighbor=minimum;
 		      container[a].right_neighbor=right;
-		      container[right].left_neighbor=a;
+		      int right=_data[_minimum].right_neighbor;
 		      _data[_minimum].right_neighbor=a;
 		      _data[a].left_neighbor=_minimum;
 		      _data[a].right_neighbor=right;
 		      _data[right].left_neighbor=a;
 		      container[a].parent=-1;
 		      container[a].marked=false;
 		      _data[a].parent=-1;
 		      _data[a].marked=false;
+		    }
 		    void cascade(int a) {
 		      if ( container[a].parent!=-1 ) {
 		        int p=container[a].parent;
 		      if ( _data[a].parent!=-1 ) {
 		        int p=_data[a].parent;
-		        if ( container[a].marked==false ) container[a].marked=true;
+		        if ( _data[a].marked==false ) _data[a].marked=true;
 		        else {
 		          cut(a,p);
 		          cascade(p);
+		        }
+		      }
+		    }
 		    void fuse(int a, int b) {
 		      unlace(b);
 		      /*Lacing b under a.*/
-		      container[b].parent=a;
+		      _data[b].parent=a;
 		      if (container[a].degree==0) {
 		        container[b].left_neighbor=b;
 		        container[b].right_neighbor=b;
 		        container[a].child=b;
 		      if (_data[a].degree==0) {
 		        _data[b].left_neighbor=b;
 		        _data[b].right_neighbor=b;
 		        _data[a].child=b;
 		      } else {
 		        int child=container[a].child;
 		        int last_child=container[child].left_neighbor;
 		        container[child].left_neighbor=b;
 		        container[b].right_neighbor=child;
 		        container[last_child].right_neighbor=b;
 		        container[b].left_neighbor=last_child;
 		        int child=_data[a].child;
 		        int last_child=_data[child].left_neighbor;
 		        _data[child].left_neighbor=b;
 		        _data[b].right_neighbor=child;
 		        _data[last_child].right_neighbor=b;
 		        _data[b].left_neighbor=last_child;
+		      }
-		      ++container[a].degree;
+		      ++_data[a].degree;
-		      container[b].marked=false;
+		      _data[b].marked=false;
+		    }
 		    /*
 		     *It is invoked only if a has siblings.
 		     */
 		    void unlace(int a) {
 		      int leftn=container[a].left_neighbor;
 		      int rightn=container[a].right_neighbor;
 		      container[leftn].right_neighbor=rightn;
 		      container[rightn].left_neighbor=leftn;
 		      int leftn=_data[a].left_neighbor;
 		      int rightn=_data[a].right_neighbor;
 		      _data[leftn].right_neighbor=rightn;
 		      _data[rightn].left_neighbor=leftn;
+		    }
-		    class store {
+		    class Store {
 		      friend class FibHeap;
 		      Item name;
 		      int parent;
 		      int left_neighbor;
 		      int right_neighbor;
 		      int child;
 		      int degree;
 		      bool marked;
 		      bool in;
 		      Prio prio;
-		      store() : parent(-1), child(-1), degree(), marked(false), in(true) {}
+		      Store() : parent(-1), child(-1), degree(), marked(false), in(true) {}
 		    };
 		  };
 		} //namespace lemon
 		#endif //LEMON_FIB_HEAP_H

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.
 		#include <vector>
 		#include <lemon/error.h>
 		namespace lemon {
 		  /// \ingroup auxdata
 		  ///
 		  /// \brief A Radix Heap implementation.
 		  ///
 		  /// 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.
 		  ///
-		  /// \param _ItemIntMap A read and writable Item int map, used internally
+		  /// \param IM A read and writable Item int map, used internally
 		  /// to handle the cross references.
 		  ///
 		  /// \see BinHeap
 		  /// \see Dijkstra
-		  template <typename _ItemIntMap>
+		  template <typename IM>
 		  class RadixHeap {
 		  public:
-		    typedef typename _ItemIntMap::Key Item;
+		    typedef typename IM::Key Item;
 		    typedef int Prio;
-		    typedef _ItemIntMap ItemIntMap;
+		    typedef IM ItemIntMap;
 		    /// \brief Exception thrown by RadixHeap.
 		    ///
 		    /// This Exception is thrown when a smaller priority
 		    /// is inserted into the \e RadixHeap then the last time erased.
 		    /// \see RadixHeap
 		    class UnderFlowPriorityError : public Exception {
 		    public:
 		      virtual const char* what() const throw() {
 		        return "lemon::RadixHeap::UnderFlowPriorityError";
+		      }
 		    };
 		    /// \brief Type to represent the items states.
 		    ///
 		    /// Each Item element have a state associated to it. It may be "in heap",
 		    /// "pre heap" or "post heap". The latter two are indifferent from the
 		    /// heap's point of view, but may be useful to the user.
 		    ///
 		    /// The ItemIntMap \e should be initialized in such way that it maps
 		    /// PRE_HEAP (-1) to any element to be put in the heap...
 		    enum State {
 		      IN_HEAP = 0,
 		      PRE_HEAP = -1,
 		      POST_HEAP = -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;
+		    ItemIntMap &_iim;
 		  public:
 		    /// \brief The constructor.
 		    ///
 		    /// The constructor.
 		    ///
-		    /// \param _iim It should be given to the constructor, since it is used
+		    /// \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 &_iim, int minimal = 0, int capacity = 0)
 		      : iim(_iim) {
 		    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)) {
 		        extend();
+		      }
+		    }
 		    /// The number of items stored in the heap.
 		    ///
 		    /// \brief Returns the number of items stored in the heap.
 		    int size() const { return data.size(); }
 		    /// \brief Checks if the heap stores no items.
 		    ///
 		    /// Returns \c true if and only if the heap stores no items.
 		    bool empty() const { return data.empty(); }
 		    /// \brief Make empty this heap.
 		    ///
 		    /// 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) {
 		      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)) {
 		        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.
 		    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.
 		    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.
 		    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.
 		    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.
 		    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.
 		    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.
 		    int findDown(int start, int pr) {
 		      while (upper(start, pr)) {
 		        if (--start < 0) throw UnderFlowPriorityError();
+		      }
 		      return start;
+		    }
 		    /// \brief Find the first not empty box.
 		    int findFirst() {
 		      int first = 0;
 		      while (boxes[first].first == -1) ++first;
 		      return first;
+		    }
 		    /// \brief Gives back the minimal prio of the 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.
 		    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;
+		        _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.
 		    /// \param i The item to insert.
 		    /// \param p The priority of the item.
 		    void push(const Item &i, const Prio &p) {
 		      int n = data.size();
-		      iim.set(i, n);
+		      _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.
 		    ///
 		    /// This method returns the item with minimum priority.
 		    /// \pre The heap must be nonempty.
 		    Item top() const {
 		      const_cast<RadixHeap<ItemIntMap>&>(*this).moveDown();
 		      return data[boxes[0].first].item;
+		    }
 		    /// \brief Returns the minimum priority.
 		    ///
 		    /// It returns the minimum priority.
 		    /// \pre The heap must be nonempty.
 		    Prio prio() const {
 		      const_cast<RadixHeap<ItemIntMap>&>(*this).moveDown();
 		      return data[boxes[0].first].prio;
+		     }
 		    /// \brief Deletes the item with minimum priority.
 		    ///
 		    /// This method deletes the item with minimum priority.
 		    /// \pre The heap must be non-empty.
 		    void pop() {
 		      moveDown();
 		      int index = boxes[0].first;
-		      iim[data[index].item] = POST_HEAP;
+		      _iim[data[index].item] = POST_HEAP;
 		      remove(index);
 		      relocate_last(index);
+		    }
 		    /// \brief Deletes \c i from the heap.
 		    ///
 		    /// This method deletes item \c i from the heap, if \c i was
 		    /// already stored in the heap.
 		    /// \param i The item to erase.
 		    void erase(const Item &i) {
 		      int index = iim[i];
 		      iim[i] = POST_HEAP;
 		      int index = _iim[i];
 		      _iim[i] = POST_HEAP;
 		      remove(index);
 		      relocate_last(index);
+		   }
 		    /// \brief Returns the priority of \c i.
 		    ///
 		    /// This function returns the priority of item \c i.
 		    /// \pre \c i must be in the heap.
 		    /// \param i The item.
 		    Prio operator[](const Item &i) const {
-		      int idx = iim[i];
+		      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.
 		    ///
 		    /// 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.
 		    /// \param i The item.
 		    /// \param p The priority.
 		    void set(const Item &i, const Prio &p) {
-		      int idx = iim[i];
+		      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.
 		    ///
 		    /// 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.
 		    /// \param i The item.
 		    /// \param p The priority.
 		    void decrease(const Item &i, const Prio &p) {
-		      int idx = iim[i];
+		      int idx = _iim[i];
 		      data[idx].prio = p;
 		      bubble_down(idx);
+		    }
 		    /// \brief Increases the priority of \c i to \c p.
 		    ///
 		    /// This method sets the priority of item \c i to \c p.
 		    /// \pre \c i must be stored in the heap with priority at most \c p
 		    /// \param i The item.
 		    /// \param p The priority.
 		    void increase(const Item &i, const Prio &p) {
-		      int idx = iim[i];
+		      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.
 		    ///
 		    /// This method returns PRE_HEAP if \c item has never been in the
 		    /// heap, IN_HEAP if it is in the heap at the moment, and POST_HEAP
 		    /// otherwise. In the latter case it is possible that \c item will
 		    /// get back to the heap again.
 		    /// \param i The item.
 		    State state(const Item &i) const {
-		      int s = iim[i];
+		      int s = _iim[i];
 		      if( s >= 0 ) s = 0;
 		      return State(s);
+		    }
 		    /// \brief Sets the state of the \c 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.
 		    /// \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;
+		        _iim[i] = st;
 		        break;
 		      case IN_HEAP:
 		        break;
+		      }
+		    }
 		  }; // class RadixHeap
 		} // namespace lemon
 		#endif // LEMON_RADIX_HEAP_H

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