1.1 --- a/lemon/concepts/heap.h Fri Oct 16 10:21:37 2009 +0200
1.2 +++ b/lemon/concepts/heap.h Thu Nov 05 15:50:01 2009 +0100
1.3 @@ -2,7 +2,7 @@
1.4 *
1.5 * This file is a part of LEMON, a generic C++ optimization library.
1.6 *
1.7 - * Copyright (C) 2003-2008
1.8 + * Copyright (C) 2003-2009
1.9 * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
1.10 * (Egervary Research Group on Combinatorial Optimization, EGRES).
1.11 *
1.12 @@ -16,14 +16,15 @@
1.13 *
1.14 */
1.15
1.16 +#ifndef LEMON_CONCEPTS_HEAP_H
1.17 +#define LEMON_CONCEPTS_HEAP_H
1.18 +
1.19 ///\ingroup concept
1.20 ///\file
1.21 ///\brief The concept of heaps.
1.22
1.23 -#ifndef LEMON_CONCEPT_HEAP_H
1.24 -#define LEMON_CONCEPT_HEAP_H
1.25 -
1.26 #include <lemon/core.h>
1.27 +#include <lemon/concept_check.h>
1.28
1.29 namespace lemon {
1.30
1.31 @@ -34,123 +35,160 @@
1.32
1.33 /// \brief The heap concept.
1.34 ///
1.35 - /// Concept class describing the main interface of heaps.
1.36 - template <typename Priority, typename ItemIntMap>
1.37 + /// This concept class describes the main interface of heaps.
1.38 + /// The various \ref heaps "heap structures" are efficient
1.39 + /// implementations of the abstract data type \e priority \e queue.
1.40 + /// They store items with specified values called \e priorities
1.41 + /// in such a way that finding and removing the item with minimum
1.42 + /// priority are efficient. The basic operations are adding and
1.43 + /// erasing items, changing the priority of an item, etc.
1.44 + ///
1.45 + /// Heaps are crucial in several algorithms, such as Dijkstra and Prim.
1.46 + /// Any class that conforms to this concept can be used easily in such
1.47 + /// algorithms.
1.48 + ///
1.49 + /// \tparam PR Type of the priorities of the items.
1.50 + /// \tparam IM A read-writable item map with \c int values, used
1.51 + /// internally to handle the cross references.
1.52 + /// \tparam CMP A functor class for comparing the priorities.
1.53 + /// The default is \c std::less<PR>.
1.54 +#ifdef DOXYGEN
1.55 + template <typename PR, typename IM, typename CMP>
1.56 +#else
1.57 + template <typename PR, typename IM, typename CMP = std::less<PR> >
1.58 +#endif
1.59 class Heap {
1.60 public:
1.61
1.62 + /// Type of the item-int map.
1.63 + typedef IM ItemIntMap;
1.64 + /// Type of the priorities.
1.65 + typedef PR Prio;
1.66 /// Type of the items stored in the heap.
1.67 typedef typename ItemIntMap::Key Item;
1.68
1.69 - /// Type of the priorities.
1.70 - typedef Priority Prio;
1.71 -
1.72 /// \brief Type to represent the states of the items.
1.73 ///
1.74 /// Each item has a state associated to it. It can be "in heap",
1.75 - /// "pre heap" or "post heap". The later two are indifferent
1.76 - /// from the point of view of the heap, but may be useful for
1.77 - /// the user.
1.78 + /// "pre-heap" or "post-heap". The latter two are indifferent from the
1.79 + /// heap's point of view, but may be useful to the user.
1.80 ///
1.81 - /// The \c ItemIntMap must be initialized in such a way, that it
1.82 - /// assigns \c PRE_HEAP (<tt>-1</tt>) to every item.
1.83 + /// The item-int map must be initialized in such way that it assigns
1.84 + /// \c PRE_HEAP (<tt>-1</tt>) to any element to be put in the heap.
1.85 enum State {
1.86 - IN_HEAP = 0,
1.87 - PRE_HEAP = -1,
1.88 - POST_HEAP = -2
1.89 + IN_HEAP = 0, ///< = 0. The "in heap" state constant.
1.90 + PRE_HEAP = -1, ///< = -1. The "pre-heap" state constant.
1.91 + POST_HEAP = -2 ///< = -2. The "post-heap" state constant.
1.92 };
1.93
1.94 - /// \brief The constructor.
1.95 + /// \brief Constructor.
1.96 ///
1.97 - /// The constructor.
1.98 + /// Constructor.
1.99 /// \param map A map that assigns \c int values to keys of type
1.100 /// \c Item. It is used internally by the heap implementations to
1.101 /// handle the cross references. The assigned value must be
1.102 - /// \c PRE_HEAP (<tt>-1</tt>) for every item.
1.103 + /// \c PRE_HEAP (<tt>-1</tt>) for each item.
1.104 explicit Heap(ItemIntMap &map) {}
1.105
1.106 + /// \brief Constructor.
1.107 + ///
1.108 + /// Constructor.
1.109 + /// \param map A map that assigns \c int values to keys of type
1.110 + /// \c Item. It is used internally by the heap implementations to
1.111 + /// handle the cross references. The assigned value must be
1.112 + /// \c PRE_HEAP (<tt>-1</tt>) for each item.
1.113 + /// \param comp The function object used for comparing the priorities.
1.114 + explicit Heap(ItemIntMap &map, const CMP &comp) {}
1.115 +
1.116 /// \brief The number of items stored in the heap.
1.117 ///
1.118 - /// Returns the number of items stored in the heap.
1.119 + /// This function returns the number of items stored in the heap.
1.120 int size() const { return 0; }
1.121
1.122 - /// \brief Checks if the heap is empty.
1.123 + /// \brief Check if the heap is empty.
1.124 ///
1.125 - /// Returns \c true if the heap is empty.
1.126 + /// This function returns \c true if the heap is empty.
1.127 bool empty() const { return false; }
1.128
1.129 - /// \brief Makes the heap empty.
1.130 + /// \brief Make the heap empty.
1.131 ///
1.132 - /// Makes the heap empty.
1.133 - void clear();
1.134 + /// This functon makes the heap empty.
1.135 + /// It does not change the cross reference map. If you want to reuse
1.136 + /// a heap that is not surely empty, you should first clear it and
1.137 + /// then you should set the cross reference map to \c PRE_HEAP
1.138 + /// for each item.
1.139 + void clear() {}
1.140
1.141 - /// \brief Inserts an item into the heap with the given priority.
1.142 + /// \brief Insert an item into the heap with the given priority.
1.143 ///
1.144 - /// Inserts the given item into the heap with the given priority.
1.145 + /// This function inserts the given item into the heap with the
1.146 + /// given priority.
1.147 /// \param i The item to insert.
1.148 /// \param p The priority of the item.
1.149 + /// \pre \e i must not be stored in the heap.
1.150 void push(const Item &i, const Prio &p) {}
1.151
1.152 - /// \brief Returns the item having minimum priority.
1.153 + /// \brief Return the item having minimum priority.
1.154 ///
1.155 - /// Returns the item having minimum priority.
1.156 + /// This function returns the item having minimum priority.
1.157 /// \pre The heap must be non-empty.
1.158 Item top() const {}
1.159
1.160 /// \brief The minimum priority.
1.161 ///
1.162 - /// Returns the minimum priority.
1.163 + /// This function returns the minimum priority.
1.164 /// \pre The heap must be non-empty.
1.165 Prio prio() const {}
1.166
1.167 - /// \brief Removes the item having minimum priority.
1.168 + /// \brief Remove the item having minimum priority.
1.169 ///
1.170 - /// Removes the item having minimum priority.
1.171 + /// This function removes the item having minimum priority.
1.172 /// \pre The heap must be non-empty.
1.173 void pop() {}
1.174
1.175 - /// \brief Removes an item from the heap.
1.176 + /// \brief Remove the given item from the heap.
1.177 ///
1.178 - /// Removes the given item from the heap if it is already stored.
1.179 + /// This function removes the given item from the heap if it is
1.180 + /// already stored.
1.181 /// \param i The item to delete.
1.182 + /// \pre \e i must be in the heap.
1.183 void erase(const Item &i) {}
1.184
1.185 - /// \brief The priority of an item.
1.186 + /// \brief The priority of the given item.
1.187 ///
1.188 - /// Returns the priority of the given item.
1.189 - /// \pre \c i must be in the heap.
1.190 + /// This function returns the priority of the given item.
1.191 /// \param i The item.
1.192 + /// \pre \e i must be in the heap.
1.193 Prio operator[](const Item &i) const {}
1.194
1.195 - /// \brief Sets the priority of an item or inserts it, if it is
1.196 + /// \brief Set the priority of an item or insert it, if it is
1.197 /// not stored in the heap.
1.198 ///
1.199 /// This method sets the priority of the given item if it is
1.200 - /// already stored in the heap.
1.201 - /// Otherwise it inserts the given item with the given priority.
1.202 + /// already stored in the heap. Otherwise it inserts the given
1.203 + /// item into the heap with the given priority.
1.204 ///
1.205 /// \param i The item.
1.206 /// \param p The priority.
1.207 void set(const Item &i, const Prio &p) {}
1.208
1.209 - /// \brief Decreases the priority of an item to the given value.
1.210 + /// \brief Decrease the priority of an item to the given value.
1.211 ///
1.212 - /// Decreases the priority of an item to the given value.
1.213 - /// \pre \c i must be stored in the heap with priority at least \c p.
1.214 + /// This function decreases the priority of an item to the given value.
1.215 /// \param i The item.
1.216 /// \param p The priority.
1.217 + /// \pre \e i must be stored in the heap with priority at least \e p.
1.218 void decrease(const Item &i, const Prio &p) {}
1.219
1.220 - /// \brief Increases the priority of an item to the given value.
1.221 + /// \brief Increase the priority of an item to the given value.
1.222 ///
1.223 - /// Increases the priority of an item to the given value.
1.224 - /// \pre \c i must be stored in the heap with priority at most \c p.
1.225 + /// This function increases the priority of an item to the given value.
1.226 /// \param i The item.
1.227 /// \param p The priority.
1.228 + /// \pre \e i must be stored in the heap with priority at most \e p.
1.229 void increase(const Item &i, const Prio &p) {}
1.230
1.231 - /// \brief Returns if an item is in, has already been in, or has
1.232 - /// never been in the heap.
1.233 + /// \brief Return the state of an item.
1.234 ///
1.235 /// This method returns \c PRE_HEAP if the given item has never
1.236 /// been in the heap, \c IN_HEAP if it is in the heap at the moment,
1.237 @@ -160,11 +198,11 @@
1.238 /// \param i The item.
1.239 State state(const Item &i) const {}
1.240
1.241 - /// \brief Sets the state of an item in the heap.
1.242 + /// \brief Set the state of an item in the heap.
1.243 ///
1.244 - /// Sets the state of the given item in the heap. It can be used
1.245 - /// to manually clear the heap when it is important to achive the
1.246 - /// better time complexity.
1.247 + /// This function sets the state of the given item in the heap.
1.248 + /// It can be used to manually clear the heap when it is important
1.249 + /// to achive better time complexity.
1.250 /// \param i The item.
1.251 /// \param st The state. It should not be \c IN_HEAP.
1.252 void state(const Item& i, State st) {}
1.253 @@ -242,4 +280,4 @@
1.254 /// @}
1.255 } // namespace lemon
1.256 }
1.257 -#endif // LEMON_CONCEPT_PATH_H
1.258 +#endif