[100] | 1 | /* -*- C++ -*- |
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| 2 | * |
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| 3 | * This file is a part of LEMON, a generic C++ optimization library |
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| 4 | * |
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| 5 | * Copyright (C) 2003-2008 |
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| 6 | * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
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| 7 | * (Egervary Research Group on Combinatorial Optimization, EGRES). |
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| 8 | * |
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| 9 | * Permission to use, modify and distribute this software is granted |
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| 10 | * provided that this copyright notice appears in all copies. For |
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| 11 | * precise terms see the accompanying LICENSE file. |
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| 12 | * |
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| 13 | * This software is provided "AS IS" with no warranty of any kind, |
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| 14 | * express or implied, and with no claim as to its suitability for any |
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| 15 | * purpose. |
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| 16 | * |
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| 17 | */ |
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| 18 | |
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| 19 | ///\ingroup concept |
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| 20 | ///\file |
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[113] | 21 | ///\brief The concept of heaps. |
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[100] | 22 | |
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| 23 | #ifndef LEMON_CONCEPT_HEAP_H |
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| 24 | #define LEMON_CONCEPT_HEAP_H |
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| 25 | |
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| 26 | #include <lemon/bits/invalid.h> |
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| 27 | |
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| 28 | namespace lemon { |
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[113] | 29 | |
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[100] | 30 | namespace concepts { |
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[113] | 31 | |
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[100] | 32 | /// \addtogroup concept |
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| 33 | /// @{ |
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| 34 | |
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[113] | 35 | /// \brief The heap concept. |
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[100] | 36 | /// |
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[113] | 37 | /// Concept class describing the main interface of heaps. |
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| 38 | template <typename Priority, typename ItemIntMap> |
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[100] | 39 | class Heap { |
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| 40 | public: |
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| 41 | |
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[113] | 42 | /// Type of the items stored in the heap. |
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| 43 | typedef typename ItemIntMap::Key Item; |
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[100] | 44 | |
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[113] | 45 | /// Type of the priorities. |
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| 46 | typedef Priority Prio; |
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| 47 | |
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| 48 | /// \brief Type to represent the states of the items. |
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[100] | 49 | /// |
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[113] | 50 | /// Each item has a state associated to it. It can be "in heap", |
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| 51 | /// "pre heap" or "post heap". The later two are indifferent |
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| 52 | /// from the point of view of the heap, but may be useful for |
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| 53 | /// the user. |
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[100] | 54 | /// |
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[113] | 55 | /// The \c ItemIntMap must be initialized in such a way, that it |
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| 56 | /// assigns \c PRE_HEAP (<tt>-1</tt>) to every item. |
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[100] | 57 | enum State { |
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| 58 | IN_HEAP = 0, |
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| 59 | PRE_HEAP = -1, |
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| 60 | POST_HEAP = -2 |
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| 61 | }; |
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| 62 | |
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| 63 | /// \brief The constructor. |
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| 64 | /// |
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| 65 | /// The constructor. |
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[113] | 66 | /// \param map A map that assigns \c int values to keys of type |
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| 67 | /// \c Item. It is used internally by the heap implementations to |
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| 68 | /// handle the cross references. The assigned value must be |
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| 69 | /// \c PRE_HEAP (<tt>-1</tt>) for every item. |
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| 70 | explicit Heap(ItemIntMap &map) {} |
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[100] | 71 | |
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| 72 | /// \brief The number of items stored in the heap. |
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| 73 | /// |
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| 74 | /// Returns the number of items stored in the heap. |
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| 75 | int size() const { return 0; } |
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| 76 | |
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[113] | 77 | /// \brief Checks if the heap is empty. |
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[100] | 78 | /// |
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[113] | 79 | /// Returns \c true if the heap is empty. |
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[100] | 80 | bool empty() const { return false; } |
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| 81 | |
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[113] | 82 | /// \brief Makes the heap empty. |
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[100] | 83 | /// |
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[113] | 84 | /// Makes the heap empty. |
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[100] | 85 | void clear(); |
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| 86 | |
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[113] | 87 | /// \brief Inserts an item into the heap with the given priority. |
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[100] | 88 | /// |
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[113] | 89 | /// Inserts the given item into the heap with the given priority. |
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[100] | 90 | /// \param i The item to insert. |
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| 91 | /// \param p The priority of the item. |
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| 92 | void push(const Item &i, const Prio &p) {} |
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| 93 | |
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[113] | 94 | /// \brief Returns the item having minimum priority. |
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[100] | 95 | /// |
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[113] | 96 | /// Returns the item having minimum priority. |
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| 97 | /// \pre The heap must be non-empty. |
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[100] | 98 | Item top() const {} |
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| 99 | |
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[113] | 100 | /// \brief The minimum priority. |
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[100] | 101 | /// |
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[113] | 102 | /// Returns the minimum priority. |
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| 103 | /// \pre The heap must be non-empty. |
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[100] | 104 | Prio prio() const {} |
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| 105 | |
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[113] | 106 | /// \brief Removes the item having minimum priority. |
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[100] | 107 | /// |
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[113] | 108 | /// Removes the item having minimum priority. |
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| 109 | /// \pre The heap must be non-empty. |
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[100] | 110 | void pop() {} |
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| 111 | |
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[113] | 112 | /// \brief Removes an item from the heap. |
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[100] | 113 | /// |
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[113] | 114 | /// Removes the given item from the heap if it is already stored. |
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| 115 | /// \param i The item to delete. |
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[100] | 116 | void erase(const Item &i) {} |
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| 117 | |
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[113] | 118 | /// \brief The priority of an item. |
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[100] | 119 | /// |
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[113] | 120 | /// Returns the priority of the given item. |
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[100] | 121 | /// \pre \c i must be in the heap. |
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| 122 | /// \param i The item. |
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| 123 | Prio operator[](const Item &i) const {} |
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| 124 | |
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[113] | 125 | /// \brief Sets the priority of an item or inserts it, if it is |
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| 126 | /// not stored in the heap. |
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[100] | 127 | /// |
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[113] | 128 | /// This method sets the priority of the given item if it is |
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| 129 | /// already stored in the heap. |
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| 130 | /// Otherwise it inserts the given item with the given priority. |
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| 131 | /// |
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| 132 | /// It may throw an \ref UnderflowPriorityException. |
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[100] | 133 | /// \param i The item. |
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| 134 | /// \param p The priority. |
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| 135 | void set(const Item &i, const Prio &p) {} |
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| 136 | |
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[113] | 137 | /// \brief Decreases the priority of an item to the given value. |
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[100] | 138 | /// |
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[113] | 139 | /// Decreases the priority of an item to the given value. |
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[100] | 140 | /// \pre \c i must be stored in the heap with priority at least \c p. |
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| 141 | /// \param i The item. |
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| 142 | /// \param p The priority. |
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| 143 | void decrease(const Item &i, const Prio &p) {} |
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| 144 | |
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[113] | 145 | /// \brief Increases the priority of an item to the given value. |
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[100] | 146 | /// |
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[113] | 147 | /// Increases the priority of an item to the given value. |
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| 148 | /// \pre \c i must be stored in the heap with priority at most \c p. |
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[100] | 149 | /// \param i The item. |
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| 150 | /// \param p The priority. |
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| 151 | void increase(const Item &i, const Prio &p) {} |
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| 152 | |
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[113] | 153 | /// \brief Returns if an item is in, has already been in, or has |
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[100] | 154 | /// never been in the heap. |
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| 155 | /// |
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[113] | 156 | /// This method returns \c PRE_HEAP if the given item has never |
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| 157 | /// been in the heap, \c IN_HEAP if it is in the heap at the moment, |
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| 158 | /// and \c POST_HEAP otherwise. |
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| 159 | /// In the latter case it is possible that the item will get back |
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| 160 | /// to the heap again. |
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[100] | 161 | /// \param i The item. |
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| 162 | State state(const Item &i) const {} |
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| 163 | |
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[113] | 164 | /// \brief Sets the state of an item in the heap. |
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[100] | 165 | /// |
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[113] | 166 | /// Sets the state of the given item in the heap. It can be used |
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| 167 | /// to manually clear the heap when it is important to achive the |
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[100] | 168 | /// better time complexity. |
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| 169 | /// \param i The item. |
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[113] | 170 | /// \param st The state. It should not be \c IN_HEAP. |
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[100] | 171 | void state(const Item& i, State st) {} |
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| 172 | |
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| 173 | |
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| 174 | template <typename _Heap> |
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| 175 | struct Constraints { |
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| 176 | public: |
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| 177 | void constraints() { |
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[113] | 178 | typedef typename _Heap::Item OwnItem; |
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| 179 | typedef typename _Heap::Prio OwnPrio; |
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| 180 | typedef typename _Heap::State OwnState; |
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| 181 | |
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[100] | 182 | Item item; |
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| 183 | Prio prio; |
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[113] | 184 | State state; |
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[100] | 185 | item=Item(); |
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| 186 | prio=Prio(); |
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| 187 | ignore_unused_variable_warning(item); |
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| 188 | ignore_unused_variable_warning(prio); |
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[113] | 189 | ignore_unused_variable_warning(state); |
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[100] | 190 | |
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[113] | 191 | OwnItem own_item; |
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| 192 | OwnPrio own_prio; |
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| 193 | OwnState own_state; |
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| 194 | own_item=Item(); |
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| 195 | own_prio=Prio(); |
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| 196 | ignore_unused_variable_warning(own_item); |
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| 197 | ignore_unused_variable_warning(own_prio); |
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| 198 | ignore_unused_variable_warning(own_state); |
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[100] | 199 | |
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[113] | 200 | _Heap heap1(map); |
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| 201 | _Heap heap2 = heap1; |
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[100] | 202 | ignore_unused_variable_warning(heap1); |
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[113] | 203 | ignore_unused_variable_warning(heap2); |
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| 204 | |
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| 205 | int s = heap.size(); |
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| 206 | bool e = heap.empty(); |
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[100] | 207 | |
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| 208 | prio = heap.prio(); |
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| 209 | item = heap.top(); |
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[113] | 210 | prio = heap[item]; |
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| 211 | own_prio = heap.prio(); |
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| 212 | own_item = heap.top(); |
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| 213 | own_prio = heap[own_item]; |
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[100] | 214 | |
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[113] | 215 | heap.push(item, prio); |
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| 216 | heap.push(own_item, own_prio); |
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[100] | 217 | heap.pop(); |
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| 218 | |
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| 219 | heap.set(item, prio); |
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| 220 | heap.decrease(item, prio); |
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| 221 | heap.increase(item, prio); |
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[113] | 222 | heap.set(own_item, own_prio); |
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| 223 | heap.decrease(own_item, own_prio); |
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| 224 | heap.increase(own_item, own_prio); |
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[100] | 225 | |
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| 226 | heap.erase(item); |
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[113] | 227 | heap.erase(own_item); |
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| 228 | heap.clear(); |
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[100] | 229 | |
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| 230 | state = heap.state(item); |
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[113] | 231 | heap.state(item, state); |
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| 232 | state = heap.state(own_item); |
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| 233 | heap.state(own_item, own_state); |
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[100] | 234 | |
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| 235 | state = _Heap::PRE_HEAP; |
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| 236 | state = _Heap::IN_HEAP; |
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| 237 | state = _Heap::POST_HEAP; |
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[113] | 238 | own_state = _Heap::PRE_HEAP; |
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| 239 | own_state = _Heap::IN_HEAP; |
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| 240 | own_state = _Heap::POST_HEAP; |
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| 241 | } |
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[100] | 242 | |
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| 243 | _Heap& heap; |
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| 244 | ItemIntMap& map; |
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| 245 | }; |
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| 246 | }; |
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| 247 | |
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| 248 | /// @} |
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| 249 | } // namespace lemon |
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| 250 | } |
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| 251 | #endif // LEMON_CONCEPT_PATH_H |
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