COIN-OR::LEMON - Graph Library

Changeset 756:0747f332c478 in lemon for lemon/concepts/heap.h


Ignore:
Timestamp:
07/08/09 17:21:30 (10 years ago)
Author:
Peter Kovacs <kpeter@…>
Branch:
default
Phase:
public
Message:

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

File:
1 edited

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  • lemon/concepts/heap.h

    r631 r756  
    1717 */
    1818
     19#ifndef LEMON_CONCEPTS_HEAP_H
     20#define LEMON_CONCEPTS_HEAP_H
     21
    1922///\ingroup concept
    2023///\file
    2124///\brief The concept of heaps.
    2225
    23 #ifndef LEMON_CONCEPTS_HEAP_H
    24 #define LEMON_CONCEPTS_HEAP_H
    25 
    2626#include <lemon/core.h>
    2727#include <lemon/concept_check.h>
     
    3636    /// \brief The heap concept.
    3737    ///
    38     /// Concept class describing the main interface of heaps. A \e heap
    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.
     38    /// This concept class describes the main interface of heaps.
     39    /// The various heap structures are efficient
     40    /// implementations of the abstract data type \e priority \e queue.
     41    /// They store items with specified values called \e priorities
     42    /// in such a way that finding and removing the item with minimum
     43    /// priority are efficient. The basic operations are adding and
     44    /// erasing items, changing the priority of an item, etc.
    4345    ///
    44     /// \tparam PR Type of the priority of the items.
    45     /// \tparam IM A read and writable item map with int values, used
     46    /// Heaps are crucial in several algorithms, such as Dijkstra and Prim.
     47    /// Any class that conforms to this concept can be used easily in such
     48    /// algorithms.
     49    ///
     50    /// \tparam PR Type of the priorities of the items.
     51    /// \tparam IM A read-writable item map with \c int values, used
    4652    /// internally to handle the cross references.
    47     /// \tparam Comp A functor class for the ordering of the priorities.
     53    /// \tparam CMP A functor class for comparing the priorities.
    4854    /// The default is \c std::less<PR>.
    4955#ifdef DOXYGEN
    50     template <typename PR, typename IM, typename Comp = std::less<PR> >
     56    template <typename PR, typename IM, typename CMP>
    5157#else
    52     template <typename PR, typename IM>
     58    template <typename PR, typename IM, typename CMP = std::less<PR> >
    5359#endif
    5460    class Heap {
     
    6571      ///
    6672      /// Each item has a state associated to it. It can be "in heap",
    67       /// "pre heap" or "post heap". The later two are indifferent
    68       /// from the point of view of the heap, but may be useful for
    69       /// the user.
     73      /// "pre-heap" or "post-heap". The latter two are indifferent from the
     74      /// heap's point of view, but may be useful to the user.
    7075      ///
    7176      /// The item-int map must be initialized in such way that it assigns
     
    7378      enum State {
    7479        IN_HEAP = 0,    ///< = 0. The "in heap" state constant.
    75         PRE_HEAP = -1,  ///< = -1. The "pre heap" state constant.
    76         POST_HEAP = -2  ///< = -2. The "post heap" state constant.
     80        PRE_HEAP = -1,  ///< = -1. The "pre-heap" state constant.
     81        POST_HEAP = -2  ///< = -2. The "post-heap" state constant.
    7782      };
    7883
    79       /// \brief The constructor.
    80       ///
    81       /// The constructor.
     84      /// \brief Constructor.
     85      ///
     86      /// Constructor.
    8287      /// \param map A map that assigns \c int values to keys of type
    8388      /// \c Item. It is used internally by the heap implementations to
    8489      /// handle the cross references. The assigned value must be
    85       /// \c PRE_HEAP (<tt>-1</tt>) for every item.
     90      /// \c PRE_HEAP (<tt>-1</tt>) for each item.
    8691      explicit Heap(ItemIntMap &map) {}
    8792
     93      /// \brief Constructor.
     94      ///
     95      /// Constructor.
     96      /// \param map A map that assigns \c int values to keys of type
     97      /// \c Item. It is used internally by the heap implementations to
     98      /// handle the cross references. The assigned value must be
     99      /// \c PRE_HEAP (<tt>-1</tt>) for each item.
     100      /// \param comp The function object used for comparing the priorities.
     101      explicit Heap(ItemIntMap &map, const CMP &comp) {}
     102
    88103      /// \brief The number of items stored in the heap.
    89104      ///
    90       /// Returns the number of items stored in the heap.
     105      /// This function returns the number of items stored in the heap.
    91106      int size() const { return 0; }
    92107
    93       /// \brief Checks if the heap is empty.
    94       ///
    95       /// Returns \c true if the heap is empty.
     108      /// \brief Check if the heap is empty.
     109      ///
     110      /// This function returns \c true if the heap is empty.
    96111      bool empty() const { return false; }
    97112
    98       /// \brief Makes the heap empty.
    99       ///
    100       /// Makes the heap empty.
    101       void clear();
    102 
    103       /// \brief Inserts an item into the heap with the given priority.
    104       ///
    105       /// Inserts the given item into the heap with the given priority.
     113      /// \brief Make the heap empty.
     114      ///
     115      /// This functon makes the heap empty.
     116      /// It does not change the cross reference map. If you want to reuse
     117      /// a heap that is not surely empty, you should first clear it and
     118      /// then you should set the cross reference map to \c PRE_HEAP
     119      /// for each item.
     120      void clear() {}
     121
     122      /// \brief Insert an item into the heap with the given priority.
     123      ///
     124      /// This function inserts the given item into the heap with the
     125      /// given priority.
    106126      /// \param i The item to insert.
    107127      /// \param p The priority of the item.
     128      /// \pre \e i must not be stored in the heap.
    108129      void push(const Item &i, const Prio &p) {}
    109130
    110       /// \brief Returns the item having minimum priority.
    111       ///
    112       /// Returns the item having minimum priority.
     131      /// \brief Return the item having minimum priority.
     132      ///
     133      /// This function returns the item having minimum priority.
    113134      /// \pre The heap must be non-empty.
    114135      Item top() const {}
     
    116137      /// \brief The minimum priority.
    117138      ///
    118       /// Returns the minimum priority.
     139      /// This function returns the minimum priority.
    119140      /// \pre The heap must be non-empty.
    120141      Prio prio() const {}
    121142
    122       /// \brief Removes the item having minimum priority.
    123       ///
    124       /// Removes the item having minimum priority.
     143      /// \brief Remove the item having minimum priority.
     144      ///
     145      /// This function removes the item having minimum priority.
    125146      /// \pre The heap must be non-empty.
    126147      void pop() {}
    127148
    128       /// \brief Removes an item from the heap.
    129       ///
    130       /// Removes the given item from the heap if it is already stored.
     149      /// \brief Remove the given item from the heap.
     150      ///
     151      /// This function removes the given item from the heap if it is
     152      /// already stored.
    131153      /// \param i The item to delete.
     154      /// \pre \e i must be in the heap.
    132155      void erase(const Item &i) {}
    133156
    134       /// \brief The priority of an item.
    135       ///
    136       /// Returns the priority of the given item.
    137       /// \param i The item.
    138       /// \pre \c i must be in the heap.
     157      /// \brief The priority of the given item.
     158      ///
     159      /// This function returns the priority of the given item.
     160      /// \param i The item.
     161      /// \pre \e i must be in the heap.
    139162      Prio operator[](const Item &i) const {}
    140163
    141       /// \brief Sets the priority of an item or inserts it, if it is
     164      /// \brief Set the priority of an item or insert it, if it is
    142165      /// not stored in the heap.
    143166      ///
    144167      /// This method sets the priority of the given item if it is
    145       /// already stored in the heap.
    146       /// Otherwise it inserts the given item with the given priority.
     168      /// already stored in the heap. Otherwise it inserts the given
     169      /// item into the heap with the given priority.
    147170      ///
    148171      /// \param i The item.
     
    150173      void set(const Item &i, const Prio &p) {}
    151174
    152       /// \brief Decreases the priority of an item to the given value.
    153       ///
    154       /// Decreases the priority of an item to the given value.
     175      /// \brief Decrease the priority of an item to the given value.
     176      ///
     177      /// This function decreases the priority of an item to the given value.
    155178      /// \param i The item.
    156179      /// \param p The priority.
    157       /// \pre \c i must be stored in the heap with priority at least \c p.
     180      /// \pre \e i must be stored in the heap with priority at least \e p.
    158181      void decrease(const Item &i, const Prio &p) {}
    159182
    160       /// \brief Increases the priority of an item to the given value.
    161       ///
    162       /// Increases the priority of an item to the given value.
     183      /// \brief Increase the priority of an item to the given value.
     184      ///
     185      /// This function increases the priority of an item to the given value.
    163186      /// \param i The item.
    164187      /// \param p The priority.
    165       /// \pre \c i must be stored in the heap with priority at most \c p.
     188      /// \pre \e i must be stored in the heap with priority at most \e p.
    166189      void increase(const Item &i, const Prio &p) {}
    167190
    168       /// \brief Returns if an item is in, has already been in, or has
    169       /// never been in the heap.
     191      /// \brief Return the state of an item.
    170192      ///
    171193      /// This method returns \c PRE_HEAP if the given item has never
     
    177199      State state(const Item &i) const {}
    178200
    179       /// \brief Sets the state of an item in the heap.
    180       ///
    181       /// Sets the state of the given item in the heap. It can be used
    182       /// to manually clear the heap when it is important to achive the
    183       /// better time complexity.
     201      /// \brief Set the state of an item in the heap.
     202      ///
     203      /// This function sets the state of the given item in the heap.
     204      /// It can be used to manually clear the heap when it is important
     205      /// to achive better time complexity.
    184206      /// \param i The item.
    185207      /// \param st The state. It should not be \c IN_HEAP.
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