[1330] | 1 | /* -*- C++ -*- |
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| 2 | * src/lemon/concept/heap.h - Part of LEMON, a generic C++ optimization library |
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| 3 | * |
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| 4 | * Copyright (C) 2005 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
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| 5 | * (Egervary Combinatorial Optimization Research Group, EGRES). |
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| 6 | * |
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| 7 | * Permission to use, modify and distribute this software is granted |
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| 8 | * provided that this copyright notice appears in all copies. For |
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| 9 | * precise terms see the accompanying LICENSE file. |
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| 10 | * |
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| 11 | * This software is provided "AS IS" with no warranty of any kind, |
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| 12 | * express or implied, and with no claim as to its suitability for any |
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| 13 | * purpose. |
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| 14 | * |
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| 15 | */ |
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| 16 | |
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| 17 | ///\ingroup concept |
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| 18 | ///\file |
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| 19 | ///\brief Classes for representing heaps. |
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| 20 | /// |
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| 21 | |
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| 22 | #ifndef LEMON_CONCEPT_HEAP_H |
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| 23 | #define LEMON_CONCEPT_HEAP_H |
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| 24 | |
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| 25 | #include <lemon/invalid.h> |
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| 26 | |
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| 27 | namespace lemon { |
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| 28 | namespace concept { |
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| 29 | /// \addtogroup concept |
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| 30 | /// @{ |
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| 31 | |
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| 32 | |
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| 33 | /// \brief A concept structure describes the main interface of heaps. |
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| 34 | /// |
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| 35 | /// A concept structure describes the main interface of heaps. |
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| 36 | /// |
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| 37 | template <typename Item, typename Prio, typename ItemIntMap> |
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| 38 | class Heap { |
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| 39 | public: |
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| 40 | |
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| 41 | |
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| 42 | /// \brief Type to represent the items states. |
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| 43 | /// |
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| 44 | /// Each Item element have a state associated to it. It may be "in heap", |
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| 45 | /// "pre heap" or "post heap". The later two are indifferent from the |
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| 46 | /// heap's point of view, but may be useful to the user. |
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| 47 | /// |
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| 48 | /// The ItemIntMap _should_ be initialized in such way, that it maps |
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| 49 | /// PRE_HEAP (-1) to any element to be put in the heap... |
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| 50 | enum state_enum { |
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| 51 | IN_HEAP = 0, |
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| 52 | PRE_HEAP = -1, |
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| 53 | POST_HEAP = -2 |
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| 54 | }; |
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| 55 | |
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| 56 | /// \brief The constructor. |
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| 57 | /// |
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| 58 | /// The constructor. |
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| 59 | /// \param _iim should be given to the constructor, since it is used |
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| 60 | /// internally to handle the cross references. The value of the map |
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| 61 | /// should be PRE_HEAP (-1) for each element. |
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| 62 | explicit Heap(ItemIntMap &_iim) {} |
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| 63 | |
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| 64 | /// The number of items stored in the heap. |
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| 65 | /// |
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| 66 | /// \brief Returns the number of items stored in the heap. |
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| 67 | int size() const { return 0; } |
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| 68 | /// \brief Checks if the heap stores no items. |
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| 69 | /// |
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| 70 | /// Returns \c true if and only if the heap stores no items. |
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| 71 | bool empty() const { return false; } |
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| 72 | |
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| 73 | /// \brief Insert an item into the heap with the given heap. |
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| 74 | /// |
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| 75 | /// Adds \c i to the heap with priority \c p. |
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| 76 | /// \param i The item to insert. |
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| 77 | /// \param p The priority of the item. |
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| 78 | void push(const Item &i, const Prio &p) {} |
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| 79 | |
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| 80 | /// \brief Returns the item with minimum priority. |
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| 81 | /// |
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| 82 | /// This method returns the item with minimum priority. |
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| 83 | /// \pre The heap must be nonempty. |
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| 84 | Item top() const {} |
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| 85 | |
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| 86 | /// \brief Returns the minimum priority. |
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| 87 | /// |
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| 88 | /// It returns the minimum priority. |
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| 89 | /// \pre The heap must be nonempty. |
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| 90 | Prio prio() const {} |
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| 91 | |
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| 92 | /// \brief Deletes the item with minimum priority. |
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| 93 | /// |
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| 94 | /// This method deletes the item with minimum priority. |
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| 95 | /// \pre The heap must be non-empty. |
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| 96 | void pop() {} |
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| 97 | |
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| 98 | /// \brief Deletes \c i from the heap. |
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| 99 | /// |
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| 100 | /// This method deletes item \c i from the heap, if \c i was |
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| 101 | /// already stored in the heap. |
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| 102 | /// \param i The item to erase. |
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| 103 | void erase(const Item &i) {} |
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| 104 | |
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| 105 | /// \brief Returns the priority of \c i. |
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| 106 | /// |
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| 107 | /// This function returns the priority of item \c i. |
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| 108 | /// \pre \c i must be in the heap. |
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| 109 | /// \param i The item. |
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| 110 | Prio operator[](const Item &i) const {} |
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| 111 | |
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| 112 | /// \brief \c i gets to the heap with priority \c p independently |
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| 113 | /// if \c i was already there. |
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| 114 | /// |
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| 115 | /// This method calls \ref push(\c i, \c p) if \c i is not stored |
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| 116 | /// in the heap and sets the priority of \c i to \c p otherwise. |
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| 117 | /// It may throw an \e UnderFlowPriorityException. |
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| 118 | /// \param i The item. |
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| 119 | /// \param p The priority. |
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| 120 | void set(const Item &i, const Prio &p) {} |
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| 121 | |
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| 122 | /// \brief Decreases the priority of \c i to \c p. |
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| 123 | /// |
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| 124 | /// This method decreases the priority of item \c i to \c p. |
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| 125 | /// \pre \c i must be stored in the heap with priority at least \c p. |
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| 126 | /// \param i The item. |
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| 127 | /// \param p The priority. |
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| 128 | void decrease(const Item &i, const Prio &p) {} |
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| 129 | |
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| 130 | /// \brief Increases the priority of \c i to \c p. |
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| 131 | /// |
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| 132 | /// This method sets the priority of item \c i to \c p. |
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| 133 | /// \pre \c i must be stored in the heap with priority at most \c |
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| 134 | /// p relative to \c Compare. |
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| 135 | /// \param i The item. |
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| 136 | /// \param p The priority. |
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| 137 | void increase(const Item &i, const Prio &p) {} |
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| 138 | |
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| 139 | /// \brief Returns if \c item is in, has already been in, or has |
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| 140 | /// never been in the heap. |
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| 141 | /// |
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| 142 | /// This method returns PRE_HEAP if \c item has never been in the |
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| 143 | /// heap, IN_HEAP if it is in the heap at the moment, and POST_HEAP |
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| 144 | /// otherwise. In the latter case it is possible that \c item will |
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| 145 | /// get back to the heap again. |
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| 146 | /// \param i The item. |
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| 147 | state_enum state(const Item &i) const {} |
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| 148 | |
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| 149 | |
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| 150 | template <typename _Heap> |
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| 151 | struct Constraints { |
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| 152 | public: |
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| 153 | |
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| 154 | void constraints() { |
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| 155 | Item item; |
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| 156 | Prio prio; |
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| 157 | |
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| 158 | ignore_unused_variable_warning(item); |
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| 159 | ignore_unused_variable_warning(prio); |
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| 160 | |
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| 161 | typedef typename _Heap::state_enum state_enum; |
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| 162 | state_enum state; |
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| 163 | |
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| 164 | ignore_unused_variable_warning(state); |
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| 165 | |
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| 166 | _Heap heap1 = _Heap(map); |
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| 167 | |
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| 168 | ignore_unused_variable_warning(heap1); |
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| 169 | |
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| 170 | heap.push(item, prio); |
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| 171 | |
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| 172 | prio = heap.prio(); |
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| 173 | item = heap.top(); |
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| 174 | |
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| 175 | heap.pop(); |
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| 176 | |
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| 177 | heap.set(item, prio); |
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| 178 | heap.decrease(item, prio); |
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| 179 | heap.increase(item, prio); |
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| 180 | prio = heap[item]; |
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| 181 | |
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| 182 | heap.erase(item); |
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| 183 | |
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| 184 | state = heap.state(item); |
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| 185 | |
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| 186 | state = _Heap::PRE_HEAP; |
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| 187 | state = _Heap::IN_HEAP; |
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| 188 | state = _Heap::POST_HEAP; |
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| 189 | } |
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| 190 | |
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| 191 | _Heap& heap; |
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| 192 | ItemIntMap& map; |
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| 193 | |
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| 194 | Constraints() : heap(0), map(0) {} |
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| 195 | }; |
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| 196 | }; |
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| 197 | |
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| 198 | /// @} |
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| 199 | } // namespace lemon |
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| 200 | } |
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| 201 | #endif // LEMON_CONCEPT_PATH_H |
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