lemon/concepts/heap.h
changeset 558 e7017ec2d5cd
parent 514 f5bc148f7e1f
child 576 33c6b6e755cd
equal deleted inserted replaced
8:9faee4d67877 9:adc360b39041
    33     /// \addtogroup concept
    33     /// \addtogroup concept
    34     /// @{
    34     /// @{
    35 
    35 
    36     /// \brief The heap concept.
    36     /// \brief The heap concept.
    37     ///
    37     ///
    38     /// Concept class describing the main interface of heaps.
    38     /// Concept class describing the main interface of heaps. A \e heap
    39     template <typename Priority, typename ItemIntMap>
    39     /// is a data structure for storing items with specified values called
       
    40     /// \e priorities in such a way that finding the item with minimum
       
    41     /// priority is efficient. In a heap one can change the priority of an
       
    42     /// item, add or erase an item, etc.
       
    43     ///
       
    44     /// \tparam PR Type of the priority of the items.
       
    45     /// \tparam IM A read and writable item map with int values, used
       
    46     /// internally to handle the cross references.
       
    47     /// \tparam Comp A functor class for the ordering of the priorities.
       
    48     /// The default is \c std::less<PR>.
       
    49 #ifdef DOXYGEN
       
    50     template <typename PR, typename IM, typename Comp = std::less<PR> >
       
    51 #else
       
    52     template <typename PR, typename IM>
       
    53 #endif
    40     class Heap {
    54     class Heap {
    41     public:
    55     public:
    42 
    56 
       
    57       /// Type of the item-int map.
       
    58       typedef IM ItemIntMap;
       
    59       /// Type of the priorities.
       
    60       typedef PR Prio;
    43       /// Type of the items stored in the heap.
    61       /// Type of the items stored in the heap.
    44       typedef typename ItemIntMap::Key Item;
    62       typedef typename ItemIntMap::Key Item;
    45 
       
    46       /// Type of the priorities.
       
    47       typedef Priority Prio;
       
    48 
    63 
    49       /// \brief Type to represent the states of the items.
    64       /// \brief Type to represent the states of the items.
    50       ///
    65       ///
    51       /// Each item has a state associated to it. It can be "in heap",
    66       /// Each item has a state associated to it. It can be "in heap",
    52       /// "pre heap" or "post heap". The later two are indifferent
    67       /// "pre heap" or "post heap". The later two are indifferent
    53       /// from the point of view of the heap, but may be useful for
    68       /// from the point of view of the heap, but may be useful for
    54       /// the user.
    69       /// the user.
    55       ///
    70       ///
    56       /// The \c ItemIntMap must be initialized in such a way, that it
    71       /// The item-int map must be initialized in such way that it assigns
    57       /// assigns \c PRE_HEAP (<tt>-1</tt>) to every item.
    72       /// \c PRE_HEAP (<tt>-1</tt>) to any element to be put in the heap.
    58       enum State {
    73       enum State {
    59         IN_HEAP = 0,
    74         IN_HEAP = 0,    ///< The "in heap" state constant.
    60         PRE_HEAP = -1,
    75         PRE_HEAP = -1,  ///< The "pre heap" state constant.
    61         POST_HEAP = -2
    76         POST_HEAP = -2  ///< The "post heap" state constant.
    62       };
    77       };
    63 
    78 
    64       /// \brief The constructor.
    79       /// \brief The constructor.
    65       ///
    80       ///
    66       /// The constructor.
    81       /// The constructor.
   117       void erase(const Item &i) {}
   132       void erase(const Item &i) {}
   118 
   133 
   119       /// \brief The priority of an item.
   134       /// \brief The priority of an item.
   120       ///
   135       ///
   121       /// Returns the priority of the given item.
   136       /// Returns the priority of the given item.
       
   137       /// \param i The item.
   122       /// \pre \c i must be in the heap.
   138       /// \pre \c i must be in the heap.
   123       /// \param i The item.
       
   124       Prio operator[](const Item &i) const {}
   139       Prio operator[](const Item &i) const {}
   125 
   140 
   126       /// \brief Sets the priority of an item or inserts it, if it is
   141       /// \brief Sets the priority of an item or inserts it, if it is
   127       /// not stored in the heap.
   142       /// not stored in the heap.
   128       ///
   143       ///
   135       void set(const Item &i, const Prio &p) {}
   150       void set(const Item &i, const Prio &p) {}
   136 
   151 
   137       /// \brief Decreases the priority of an item to the given value.
   152       /// \brief Decreases the priority of an item to the given value.
   138       ///
   153       ///
   139       /// Decreases the priority of an item to the given value.
   154       /// Decreases the priority of an item to the given value.
       
   155       /// \param i The item.
       
   156       /// \param p The priority.
   140       /// \pre \c i must be stored in the heap with priority at least \c p.
   157       /// \pre \c i must be stored in the heap with priority at least \c p.
       
   158       void decrease(const Item &i, const Prio &p) {}
       
   159 
       
   160       /// \brief Increases the priority of an item to the given value.
       
   161       ///
       
   162       /// Increases the priority of an item to the given value.
   141       /// \param i The item.
   163       /// \param i The item.
   142       /// \param p The priority.
   164       /// \param p The priority.
   143       void decrease(const Item &i, const Prio &p) {}
       
   144 
       
   145       /// \brief Increases the priority of an item to the given value.
       
   146       ///
       
   147       /// Increases the priority of an item to the given value.
       
   148       /// \pre \c i must be stored in the heap with priority at most \c p.
   165       /// \pre \c i must be stored in the heap with priority at most \c p.
   149       /// \param i The item.
       
   150       /// \param p The priority.
       
   151       void increase(const Item &i, const Prio &p) {}
   166       void increase(const Item &i, const Prio &p) {}
   152 
   167 
   153       /// \brief Returns if an item is in, has already been in, or has
   168       /// \brief Returns if an item is in, has already been in, or has
   154       /// never been in the heap.
   169       /// never been in the heap.
   155       ///
   170       ///