1.1 --- a/lemon/concepts/heap.h Thu Jun 11 23:13:24 2009 +0200
1.2 +++ b/lemon/concepts/heap.h Wed Jul 08 17:21:30 2009 +0200
1.3 @@ -16,13 +16,13 @@
1.4 *
1.5 */
1.6
1.7 +#ifndef LEMON_CONCEPTS_HEAP_H
1.8 +#define LEMON_CONCEPTS_HEAP_H
1.9 +
1.10 ///\ingroup concept
1.11 ///\file
1.12 ///\brief The concept of heaps.
1.13
1.14 -#ifndef LEMON_CONCEPTS_HEAP_H
1.15 -#define LEMON_CONCEPTS_HEAP_H
1.16 -
1.17 #include <lemon/core.h>
1.18 #include <lemon/concept_check.h>
1.19
1.20 @@ -35,21 +35,27 @@
1.21
1.22 /// \brief The heap concept.
1.23 ///
1.24 - /// Concept class describing the main interface of heaps. A \e heap
1.25 - /// is a data structure for storing items with specified values called
1.26 - /// \e priorities in such a way that finding the item with minimum
1.27 - /// priority is efficient. In a heap one can change the priority of an
1.28 - /// item, add or erase an item, etc.
1.29 + /// This concept class describes the main interface of heaps.
1.30 + /// The various heap structures are efficient
1.31 + /// implementations of the abstract data type \e priority \e queue.
1.32 + /// They store items with specified values called \e priorities
1.33 + /// in such a way that finding and removing the item with minimum
1.34 + /// priority are efficient. The basic operations are adding and
1.35 + /// erasing items, changing the priority of an item, etc.
1.36 ///
1.37 - /// \tparam PR Type of the priority of the items.
1.38 - /// \tparam IM A read and writable item map with int values, used
1.39 + /// Heaps are crucial in several algorithms, such as Dijkstra and Prim.
1.40 + /// Any class that conforms to this concept can be used easily in such
1.41 + /// algorithms.
1.42 + ///
1.43 + /// \tparam PR Type of the priorities of the items.
1.44 + /// \tparam IM A read-writable item map with \c int values, used
1.45 /// internally to handle the cross references.
1.46 - /// \tparam Comp A functor class for the ordering of the priorities.
1.47 + /// \tparam CMP A functor class for comparing the priorities.
1.48 /// The default is \c std::less<PR>.
1.49 #ifdef DOXYGEN
1.50 - template <typename PR, typename IM, typename Comp = std::less<PR> >
1.51 + template <typename PR, typename IM, typename CMP>
1.52 #else
1.53 - template <typename PR, typename IM>
1.54 + template <typename PR, typename IM, typename CMP = std::less<PR> >
1.55 #endif
1.56 class Heap {
1.57 public:
1.58 @@ -64,109 +70,125 @@
1.59 /// \brief Type to represent the states of the items.
1.60 ///
1.61 /// Each item has a state associated to it. It can be "in heap",
1.62 - /// "pre heap" or "post heap". The later two are indifferent
1.63 - /// from the point of view of the heap, but may be useful for
1.64 - /// the user.
1.65 + /// "pre-heap" or "post-heap". The latter two are indifferent from the
1.66 + /// heap's point of view, but may be useful to the user.
1.67 ///
1.68 /// The item-int map must be initialized in such way that it assigns
1.69 /// \c PRE_HEAP (<tt>-1</tt>) to any element to be put in the heap.
1.70 enum State {
1.71 IN_HEAP = 0, ///< = 0. The "in heap" state constant.
1.72 - PRE_HEAP = -1, ///< = -1. The "pre heap" state constant.
1.73 - POST_HEAP = -2 ///< = -2. The "post heap" state constant.
1.74 + PRE_HEAP = -1, ///< = -1. The "pre-heap" state constant.
1.75 + POST_HEAP = -2 ///< = -2. The "post-heap" state constant.
1.76 };
1.77
1.78 - /// \brief The constructor.
1.79 + /// \brief Constructor.
1.80 ///
1.81 - /// The constructor.
1.82 + /// Constructor.
1.83 /// \param map A map that assigns \c int values to keys of type
1.84 /// \c Item. It is used internally by the heap implementations to
1.85 /// handle the cross references. The assigned value must be
1.86 - /// \c PRE_HEAP (<tt>-1</tt>) for every item.
1.87 + /// \c PRE_HEAP (<tt>-1</tt>) for each item.
1.88 explicit Heap(ItemIntMap &map) {}
1.89
1.90 + /// \brief Constructor.
1.91 + ///
1.92 + /// Constructor.
1.93 + /// \param map A map that assigns \c int values to keys of type
1.94 + /// \c Item. It is used internally by the heap implementations to
1.95 + /// handle the cross references. The assigned value must be
1.96 + /// \c PRE_HEAP (<tt>-1</tt>) for each item.
1.97 + /// \param comp The function object used for comparing the priorities.
1.98 + explicit Heap(ItemIntMap &map, const CMP &comp) {}
1.99 +
1.100 /// \brief The number of items stored in the heap.
1.101 ///
1.102 - /// Returns the number of items stored in the heap.
1.103 + /// This function returns the number of items stored in the heap.
1.104 int size() const { return 0; }
1.105
1.106 - /// \brief Checks if the heap is empty.
1.107 + /// \brief Check if the heap is empty.
1.108 ///
1.109 - /// Returns \c true if the heap is empty.
1.110 + /// This function returns \c true if the heap is empty.
1.111 bool empty() const { return false; }
1.112
1.113 - /// \brief Makes the heap empty.
1.114 + /// \brief Make the heap empty.
1.115 ///
1.116 - /// Makes the heap empty.
1.117 - void clear();
1.118 + /// This functon makes the heap empty.
1.119 + /// It does not change the cross reference map. If you want to reuse
1.120 + /// a heap that is not surely empty, you should first clear it and
1.121 + /// then you should set the cross reference map to \c PRE_HEAP
1.122 + /// for each item.
1.123 + void clear() {}
1.124
1.125 - /// \brief Inserts an item into the heap with the given priority.
1.126 + /// \brief Insert an item into the heap with the given priority.
1.127 ///
1.128 - /// Inserts the given item into the heap with the given priority.
1.129 + /// This function inserts the given item into the heap with the
1.130 + /// given priority.
1.131 /// \param i The item to insert.
1.132 /// \param p The priority of the item.
1.133 + /// \pre \e i must not be stored in the heap.
1.134 void push(const Item &i, const Prio &p) {}
1.135
1.136 - /// \brief Returns the item having minimum priority.
1.137 + /// \brief Return the item having minimum priority.
1.138 ///
1.139 - /// Returns the item having minimum priority.
1.140 + /// This function returns the item having minimum priority.
1.141 /// \pre The heap must be non-empty.
1.142 Item top() const {}
1.143
1.144 /// \brief The minimum priority.
1.145 ///
1.146 - /// Returns the minimum priority.
1.147 + /// This function returns the minimum priority.
1.148 /// \pre The heap must be non-empty.
1.149 Prio prio() const {}
1.150
1.151 - /// \brief Removes the item having minimum priority.
1.152 + /// \brief Remove the item having minimum priority.
1.153 ///
1.154 - /// Removes the item having minimum priority.
1.155 + /// This function removes the item having minimum priority.
1.156 /// \pre The heap must be non-empty.
1.157 void pop() {}
1.158
1.159 - /// \brief Removes an item from the heap.
1.160 + /// \brief Remove the given item from the heap.
1.161 ///
1.162 - /// Removes the given item from the heap if it is already stored.
1.163 + /// This function removes the given item from the heap if it is
1.164 + /// already stored.
1.165 /// \param i The item to delete.
1.166 + /// \pre \e i must be in the heap.
1.167 void erase(const Item &i) {}
1.168
1.169 - /// \brief The priority of an item.
1.170 + /// \brief The priority of the given item.
1.171 ///
1.172 - /// Returns the priority of the given item.
1.173 + /// This function returns the priority of the given item.
1.174 /// \param i The item.
1.175 - /// \pre \c i must be in the heap.
1.176 + /// \pre \e i must be in the heap.
1.177 Prio operator[](const Item &i) const {}
1.178
1.179 - /// \brief Sets the priority of an item or inserts it, if it is
1.180 + /// \brief Set the priority of an item or insert it, if it is
1.181 /// not stored in the heap.
1.182 ///
1.183 /// This method sets the priority of the given item if it is
1.184 - /// already stored in the heap.
1.185 - /// Otherwise it inserts the given item with the given priority.
1.186 + /// already stored in the heap. Otherwise it inserts the given
1.187 + /// item into the heap with the given priority.
1.188 ///
1.189 /// \param i The item.
1.190 /// \param p The priority.
1.191 void set(const Item &i, const Prio &p) {}
1.192
1.193 - /// \brief Decreases the priority of an item to the given value.
1.194 + /// \brief Decrease the priority of an item to the given value.
1.195 ///
1.196 - /// Decreases the priority of an item to the given value.
1.197 + /// This function decreases the priority of an item to the given value.
1.198 /// \param i The item.
1.199 /// \param p The priority.
1.200 - /// \pre \c i must be stored in the heap with priority at least \c p.
1.201 + /// \pre \e i must be stored in the heap with priority at least \e p.
1.202 void decrease(const Item &i, const Prio &p) {}
1.203
1.204 - /// \brief Increases the priority of an item to the given value.
1.205 + /// \brief Increase the priority of an item to the given value.
1.206 ///
1.207 - /// Increases the priority of an item to the given value.
1.208 + /// This function increases the priority of an item to the given value.
1.209 /// \param i The item.
1.210 /// \param p The priority.
1.211 - /// \pre \c i must be stored in the heap with priority at most \c p.
1.212 + /// \pre \e i must be stored in the heap with priority at most \e p.
1.213 void increase(const Item &i, const Prio &p) {}
1.214
1.215 - /// \brief Returns if an item is in, has already been in, or has
1.216 - /// never been in the heap.
1.217 + /// \brief Return the state of an item.
1.218 ///
1.219 /// This method returns \c PRE_HEAP if the given item has never
1.220 /// been in the heap, \c IN_HEAP if it is in the heap at the moment,
1.221 @@ -176,11 +198,11 @@
1.222 /// \param i The item.
1.223 State state(const Item &i) const {}
1.224
1.225 - /// \brief Sets the state of an item in the heap.
1.226 + /// \brief Set the state of an item in the heap.
1.227 ///
1.228 - /// Sets the state of the given item in the heap. It can be used
1.229 - /// to manually clear the heap when it is important to achive the
1.230 - /// better time complexity.
1.231 + /// This function sets the state of the given item in the heap.
1.232 + /// It can be used to manually clear the heap when it is important
1.233 + /// to achive better time complexity.
1.234 /// \param i The item.
1.235 /// \param st The state. It should not be \c IN_HEAP.
1.236 void state(const Item& i, State st) {}