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) 2003-2007 |
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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 | #ifndef LEMON_BUCKET_HEAP_H |
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20 | #define LEMON_BUCKET_HEAP_H |
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21 | |
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22 | ///\ingroup auxdat |
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23 | ///\file |
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24 | ///\brief Bucket Heap implementation. |
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25 | |
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26 | #include <vector> |
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27 | #include <utility> |
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28 | #include <functional> |
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29 | |
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30 | namespace lemon { |
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31 | |
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32 | /// \ingroup auxdat |
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33 | /// |
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34 | /// \brief A Bucket Heap implementation. |
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35 | /// |
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36 | /// This class implements the \e bucket \e heap data structure. A \e heap |
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37 | /// is a data structure for storing items with specified values called \e |
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38 | /// priorities in such a way that finding the item with minimum priority is |
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39 | /// efficient. The bucket heap is very simple implementation, it can store |
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40 | /// only integer priorities and it stores for each priority in the |
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41 | /// \f$ [0..C) \f$ range a list of items. So it should be used only when |
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42 | /// the priorities are small. It is not intended to use as dijkstra heap. |
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43 | /// |
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44 | /// \param _ItemIntMap A read and writable Item int map, used internally |
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45 | /// to handle the cross references. |
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46 | /// \param minimize If the given parameter is true then the heap gives back |
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47 | /// the lowest priority. |
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48 | template <typename _ItemIntMap, bool minimize = true > |
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49 | class BucketHeap { |
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50 | |
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51 | public: |
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52 | typedef typename _ItemIntMap::Key Item; |
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53 | typedef int Prio; |
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54 | typedef std::pair<Item, Prio> Pair; |
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55 | typedef _ItemIntMap ItemIntMap; |
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56 | |
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57 | /// \brief Type to represent the items states. |
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58 | /// |
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59 | /// Each Item element have a state associated to it. It may be "in heap", |
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60 | /// "pre heap" or "post heap". The latter two are indifferent from the |
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61 | /// heap's point of view, but may be useful to the user. |
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62 | /// |
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63 | /// The ItemIntMap \e should be initialized in such way that it maps |
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64 | /// PRE_HEAP (-1) to any element to be put in the heap... |
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65 | enum state_enum { |
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66 | IN_HEAP = 0, |
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67 | PRE_HEAP = -1, |
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68 | POST_HEAP = -2 |
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69 | }; |
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70 | |
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71 | public: |
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72 | /// \brief The constructor. |
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73 | /// |
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74 | /// The constructor. |
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75 | /// \param _index should be given to the constructor, since it is used |
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76 | /// internally to handle the cross references. The value of the map |
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77 | /// should be PRE_HEAP (-1) for each element. |
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78 | explicit BucketHeap(ItemIntMap &_index) : index(_index), minimal(0) {} |
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79 | |
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80 | /// The number of items stored in the heap. |
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81 | /// |
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82 | /// \brief Returns the number of items stored in the heap. |
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83 | int size() const { return data.size(); } |
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84 | |
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85 | /// \brief Checks if the heap stores no items. |
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86 | /// |
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87 | /// Returns \c true if and only if the heap stores no items. |
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88 | bool empty() const { return data.empty(); } |
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89 | |
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90 | /// \brief Make empty this heap. |
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91 | /// |
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92 | /// Make empty this heap. It does not change the cross reference |
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93 | /// map. If you want to reuse a heap what is not surely empty you |
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94 | /// should first clear the heap and after that you should set the |
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95 | /// cross reference map for each item to \c PRE_HEAP. |
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96 | void clear() { |
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97 | data.clear(); first.clear(); minimal = 0; |
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98 | } |
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99 | |
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100 | private: |
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101 | |
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102 | void relocate_last(int idx) { |
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103 | if (idx + 1 < int(data.size())) { |
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104 | data[idx] = data.back(); |
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105 | if (data[idx].prev != -1) { |
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106 | data[data[idx].prev].next = idx; |
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107 | } else { |
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108 | first[data[idx].value] = idx; |
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109 | } |
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110 | if (data[idx].next != -1) { |
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111 | data[data[idx].next].prev = idx; |
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112 | } |
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113 | index[data[idx].item] = idx; |
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114 | } |
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115 | data.pop_back(); |
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116 | } |
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117 | |
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118 | void unlace(int idx) { |
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119 | if (data[idx].prev != -1) { |
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120 | data[data[idx].prev].next = data[idx].next; |
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121 | } else { |
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122 | first[data[idx].value] = data[idx].next; |
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123 | } |
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124 | if (data[idx].next != -1) { |
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125 | data[data[idx].next].prev = data[idx].prev; |
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126 | } |
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127 | } |
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128 | |
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129 | void lace(int idx) { |
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130 | if (int(first.size()) <= data[idx].value) { |
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131 | first.resize(data[idx].value + 1, -1); |
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132 | } |
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133 | data[idx].next = first[data[idx].value]; |
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134 | if (data[idx].next != -1) { |
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135 | data[data[idx].next].prev = idx; |
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136 | } |
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137 | first[data[idx].value] = idx; |
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138 | data[idx].prev = -1; |
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139 | } |
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140 | |
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141 | public: |
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142 | /// \brief Insert a pair of item and priority into the heap. |
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143 | /// |
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144 | /// Adds \c p.first to the heap with priority \c p.second. |
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145 | /// \param p The pair to insert. |
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146 | void push(const Pair& p) { |
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147 | push(p.first, p.second); |
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148 | } |
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149 | |
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150 | /// \brief Insert an item into the heap with the given priority. |
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151 | /// |
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152 | /// Adds \c i to the heap with priority \c p. |
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153 | /// \param i The item to insert. |
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154 | /// \param p The priority of the item. |
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155 | void push(const Item &i, const Prio &p) { |
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156 | int idx = data.size(); |
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157 | index[i] = idx; |
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158 | data.push_back(BucketItem(i, p)); |
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159 | lace(idx); |
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160 | if (p < minimal) { |
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161 | minimal = p; |
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162 | } |
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163 | } |
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164 | |
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165 | /// \brief Returns the item with minimum priority. |
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166 | /// |
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167 | /// This method returns the item with minimum priority. |
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168 | /// \pre The heap must be nonempty. |
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169 | Item top() const { |
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170 | while (first[minimal] == -1) { |
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171 | ++minimal; |
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172 | } |
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173 | return data[first[minimal]].item; |
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174 | } |
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175 | |
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176 | /// \brief Returns the minimum priority. |
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177 | /// |
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178 | /// It returns the minimum priority. |
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179 | /// \pre The heap must be nonempty. |
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180 | Prio prio() const { |
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181 | while (first[minimal] == -1) { |
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182 | ++minimal; |
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183 | } |
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184 | return minimal; |
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185 | } |
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186 | |
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187 | /// \brief Deletes the item with minimum priority. |
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188 | /// |
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189 | /// This method deletes the item with minimum priority from the heap. |
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190 | /// \pre The heap must be non-empty. |
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191 | void pop() { |
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192 | while (first[minimal] == -1) { |
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193 | ++minimal; |
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194 | } |
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195 | int idx = first[minimal]; |
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196 | index[data[idx].item] = -2; |
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197 | unlace(idx); |
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198 | relocate_last(idx); |
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199 | } |
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200 | |
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201 | /// \brief Deletes \c i from the heap. |
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202 | /// |
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203 | /// This method deletes item \c i from the heap, if \c i was |
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204 | /// already stored in the heap. |
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205 | /// \param i The item to erase. |
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206 | void erase(const Item &i) { |
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207 | int idx = index[i]; |
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208 | index[data[idx].item] = -2; |
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209 | unlace(idx); |
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210 | relocate_last(idx); |
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211 | } |
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212 | |
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213 | |
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214 | /// \brief Returns the priority of \c i. |
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215 | /// |
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216 | /// This function returns the priority of item \c i. |
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217 | /// \pre \c i must be in the heap. |
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218 | /// \param i The item. |
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219 | Prio operator[](const Item &i) const { |
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220 | int idx = index[i]; |
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221 | return data[idx].value; |
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222 | } |
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223 | |
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224 | /// \brief \c i gets to the heap with priority \c p independently |
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225 | /// if \c i was already there. |
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226 | /// |
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227 | /// This method calls \ref push(\c i, \c p) if \c i is not stored |
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228 | /// in the heap and sets the priority of \c i to \c p otherwise. |
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229 | /// \param i The item. |
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230 | /// \param p The priority. |
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231 | void set(const Item &i, const Prio &p) { |
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232 | int idx = index[i]; |
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233 | if (idx < 0) { |
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234 | push(i,p); |
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235 | } else if (p > data[idx].value) { |
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236 | increase(i, p); |
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237 | } else { |
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238 | decrease(i, p); |
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239 | } |
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240 | } |
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241 | |
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242 | /// \brief Decreases the priority of \c i to \c p. |
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243 | /// |
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244 | /// This method decreases the priority of item \c i to \c p. |
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245 | /// \pre \c i must be stored in the heap with priority at least \c |
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246 | /// p relative to \c Compare. |
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247 | /// \param i The item. |
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248 | /// \param p The priority. |
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249 | void decrease(const Item &i, const Prio &p) { |
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250 | int idx = index[i]; |
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251 | unlace(idx); |
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252 | data[idx].value = p; |
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253 | if (p < minimal) { |
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254 | minimal = p; |
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255 | } |
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256 | lace(idx); |
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257 | } |
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258 | |
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259 | /// \brief Increases the priority of \c i to \c p. |
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260 | /// |
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261 | /// This method sets the priority of item \c i to \c p. |
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262 | /// \pre \c i must be stored in the heap with priority at most \c |
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263 | /// p relative to \c Compare. |
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264 | /// \param i The item. |
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265 | /// \param p The priority. |
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266 | void increase(const Item &i, const Prio &p) { |
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267 | int idx = index[i]; |
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268 | unlace(idx); |
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269 | data[idx].value = p; |
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270 | lace(idx); |
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271 | } |
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272 | |
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273 | /// \brief Returns if \c item is in, has already been in, or has |
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274 | /// never been in the heap. |
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275 | /// |
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276 | /// This method returns PRE_HEAP if \c item has never been in the |
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277 | /// heap, IN_HEAP if it is in the heap at the moment, and POST_HEAP |
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278 | /// otherwise. In the latter case it is possible that \c item will |
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279 | /// get back to the heap again. |
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280 | /// \param i The item. |
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281 | state_enum state(const Item &i) const { |
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282 | int idx = index[i]; |
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283 | if (idx >= 0) idx = 0; |
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284 | return state_enum(idx); |
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285 | } |
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286 | |
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287 | /// \brief Sets the state of the \c item in the heap. |
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288 | /// |
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289 | /// Sets the state of the \c item in the heap. It can be used to |
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290 | /// manually clear the heap when it is important to achive the |
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291 | /// better time complexity. |
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292 | /// \param i The item. |
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293 | /// \param st The state. It should not be \c IN_HEAP. |
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294 | void state(const Item& i, state_enum st) { |
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295 | switch (st) { |
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296 | case POST_HEAP: |
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297 | case PRE_HEAP: |
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298 | if (state(i) == IN_HEAP) { |
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299 | erase(i); |
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300 | } |
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301 | index[i] = st; |
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302 | break; |
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303 | case IN_HEAP: |
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304 | break; |
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305 | } |
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306 | } |
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307 | |
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308 | private: |
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309 | |
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310 | struct BucketItem { |
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311 | BucketItem(const Item& _item, int _value) |
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312 | : item(_item), value(_value) {} |
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313 | |
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314 | Item item; |
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315 | int value; |
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316 | |
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317 | int prev, next; |
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318 | }; |
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319 | |
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320 | ItemIntMap& index; |
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321 | std::vector<int> first; |
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322 | std::vector<BucketItem> data; |
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323 | mutable int minimal; |
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324 | |
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325 | }; // class BucketHeap |
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326 | |
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327 | |
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328 | template <typename _ItemIntMap> |
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329 | class BucketHeap<_ItemIntMap, false> { |
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330 | |
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331 | public: |
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332 | typedef typename _ItemIntMap::Key Item; |
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333 | typedef int Prio; |
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334 | typedef std::pair<Item, Prio> Pair; |
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335 | typedef _ItemIntMap ItemIntMap; |
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336 | |
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337 | enum state_enum { |
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338 | IN_HEAP = 0, |
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339 | PRE_HEAP = -1, |
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340 | POST_HEAP = -2 |
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341 | }; |
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342 | |
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343 | public: |
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344 | |
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345 | explicit BucketHeap(ItemIntMap &_index) : index(_index), maximal(-1) {} |
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346 | |
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347 | int size() const { return data.size(); } |
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348 | bool empty() const { return data.empty(); } |
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349 | |
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350 | void clear() { |
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351 | data.clear(); first.clear(); maximal = -1; |
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352 | } |
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353 | |
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354 | private: |
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355 | |
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356 | void relocate_last(int idx) { |
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357 | if (idx + 1 != int(data.size())) { |
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358 | data[idx] = data.back(); |
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359 | if (data[idx].prev != -1) { |
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360 | data[data[idx].prev].next = idx; |
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361 | } else { |
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362 | first[data[idx].value] = idx; |
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363 | } |
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364 | if (data[idx].next != -1) { |
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365 | data[data[idx].next].prev = idx; |
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366 | } |
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367 | index[data[idx].item] = idx; |
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368 | } |
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369 | data.pop_back(); |
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370 | } |
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371 | |
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372 | void unlace(int idx) { |
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373 | if (data[idx].prev != -1) { |
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374 | data[data[idx].prev].next = data[idx].next; |
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375 | } else { |
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376 | first[data[idx].value] = data[idx].next; |
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377 | } |
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378 | if (data[idx].next != -1) { |
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379 | data[data[idx].next].prev = data[idx].prev; |
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380 | } |
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381 | } |
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382 | |
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383 | void lace(int idx) { |
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384 | if (int(first.size()) <= data[idx].value) { |
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385 | first.resize(data[idx].value + 1, -1); |
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386 | } |
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387 | data[idx].next = first[data[idx].value]; |
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388 | if (data[idx].next != -1) { |
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389 | data[data[idx].next].prev = idx; |
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390 | } |
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391 | first[data[idx].value] = idx; |
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392 | data[idx].prev = -1; |
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393 | } |
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394 | |
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395 | public: |
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396 | |
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397 | void push(const Pair& p) { |
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398 | push(p.first, p.second); |
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399 | } |
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400 | |
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401 | void push(const Item &i, const Prio &p) { |
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402 | int idx = data.size(); |
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403 | index[i] = idx; |
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404 | data.push_back(BucketItem(i, p)); |
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405 | lace(idx); |
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406 | if (data[idx].value > maximal) { |
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407 | maximal = data[idx].value; |
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408 | } |
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409 | } |
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410 | |
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411 | Item top() const { |
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412 | while (first[maximal] == -1) { |
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413 | --maximal; |
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414 | } |
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415 | return data[first[maximal]].item; |
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416 | } |
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417 | |
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418 | Prio prio() const { |
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419 | while (first[maximal] == -1) { |
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420 | --maximal; |
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421 | } |
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422 | return maximal; |
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423 | } |
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424 | |
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425 | void pop() { |
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426 | while (first[maximal] == -1) { |
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427 | --maximal; |
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428 | } |
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429 | int idx = first[maximal]; |
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430 | index[data[idx].item] = -2; |
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431 | unlace(idx); |
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432 | relocate_last(idx); |
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433 | } |
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434 | |
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435 | void erase(const Item &i) { |
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436 | int idx = index[i]; |
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437 | index[data[idx].item] = -2; |
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438 | unlace(idx); |
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439 | relocate_last(idx); |
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440 | } |
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441 | |
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442 | Prio operator[](const Item &i) const { |
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443 | int idx = index[i]; |
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444 | return data[idx].value; |
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445 | } |
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446 | |
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447 | void set(const Item &i, const Prio &p) { |
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448 | int idx = index[i]; |
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449 | if (idx < 0) { |
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450 | push(i,p); |
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451 | } else if (p > data[idx].value) { |
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452 | decrease(i, p); |
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453 | } else { |
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454 | increase(i, p); |
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455 | } |
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456 | } |
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457 | |
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458 | void decrease(const Item &i, const Prio &p) { |
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459 | int idx = index[i]; |
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460 | unlace(idx); |
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461 | data[idx].value = p; |
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462 | if (p > maximal) { |
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463 | maximal = p; |
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464 | } |
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465 | lace(idx); |
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466 | } |
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467 | |
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468 | void increase(const Item &i, const Prio &p) { |
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469 | int idx = index[i]; |
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470 | unlace(idx); |
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471 | data[idx].value = p; |
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472 | lace(idx); |
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473 | } |
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474 | |
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475 | state_enum state(const Item &i) const { |
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476 | int idx = index[i]; |
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477 | if (idx >= 0) idx = 0; |
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478 | return state_enum(idx); |
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479 | } |
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480 | |
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481 | void state(const Item& i, state_enum st) { |
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482 | switch (st) { |
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483 | case POST_HEAP: |
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484 | case PRE_HEAP: |
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485 | if (state(i) == IN_HEAP) { |
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486 | erase(i); |
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487 | } |
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488 | index[i] = st; |
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489 | break; |
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490 | case IN_HEAP: |
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491 | break; |
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492 | } |
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493 | } |
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494 | |
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495 | private: |
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496 | |
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497 | struct BucketItem { |
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498 | BucketItem(const Item& _item, int _value) |
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499 | : item(_item), value(_value) {} |
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500 | |
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501 | Item item; |
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502 | int value; |
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503 | |
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504 | int prev, next; |
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505 | }; |
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506 | |
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507 | ItemIntMap& index; |
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508 | std::vector<int> first; |
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509 | std::vector<BucketItem> data; |
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510 | mutable int maximal; |
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511 | |
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512 | }; // class BucketHeap |
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513 | |
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514 | /// \ingroup auxdat |
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515 | /// |
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516 | /// \brief A Simplified Bucket Heap implementation. |
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517 | /// |
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518 | /// This class implements a simplified \e bucket \e heap data |
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519 | /// structure. It does not provide some functionality but it faster |
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520 | /// and simplier data structure than the BucketHeap. The main |
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521 | /// difference is that the BucketHeap stores for every key a double |
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522 | /// linked list while this class stores just simple lists. In the |
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523 | /// other way it does not supports erasing each elements just the |
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524 | /// minimal and it does not supports key increasing, decreasing. |
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525 | /// |
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526 | /// \param _ItemIntMap A read and writable Item int map, used internally |
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527 | /// to handle the cross references. |
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528 | /// \param minimize If the given parameter is true then the heap gives back |
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529 | /// the lowest priority. |
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530 | /// |
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531 | /// \sa BucketHeap |
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532 | template <typename _ItemIntMap, bool minimize = true > |
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533 | class SimpleBucketHeap { |
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534 | |
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535 | public: |
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536 | typedef typename _ItemIntMap::Key Item; |
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537 | typedef int Prio; |
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538 | typedef std::pair<Item, Prio> Pair; |
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539 | typedef _ItemIntMap ItemIntMap; |
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540 | |
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541 | /// \brief Type to represent the items states. |
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542 | /// |
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543 | /// Each Item element have a state associated to it. It may be "in heap", |
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544 | /// "pre heap" or "post heap". The latter two are indifferent from the |
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545 | /// heap's point of view, but may be useful to the user. |
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546 | /// |
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547 | /// The ItemIntMap \e should be initialized in such way that it maps |
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548 | /// PRE_HEAP (-1) to any element to be put in the heap... |
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549 | enum state_enum { |
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550 | IN_HEAP = 0, |
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551 | PRE_HEAP = -1, |
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552 | POST_HEAP = -2 |
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553 | }; |
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554 | |
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555 | public: |
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556 | |
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557 | /// \brief The constructor. |
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558 | /// |
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559 | /// The constructor. |
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560 | /// \param _index should be given to the constructor, since it is used |
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561 | /// internally to handle the cross references. The value of the map |
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562 | /// should be PRE_HEAP (-1) for each element. |
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563 | explicit SimpleBucketHeap(ItemIntMap &_index) |
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564 | : index(_index), free(-1), num(0), minimal(0) {} |
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565 | |
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566 | /// \brief Returns the number of items stored in the heap. |
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567 | /// |
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568 | /// The number of items stored in the heap. |
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569 | int size() const { return num; } |
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570 | |
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571 | /// \brief Checks if the heap stores no items. |
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572 | /// |
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573 | /// Returns \c true if and only if the heap stores no items. |
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574 | bool empty() const { return num == 0; } |
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575 | |
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576 | /// \brief Make empty this heap. |
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577 | /// |
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578 | /// Make empty this heap. It does not change the cross reference |
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579 | /// map. If you want to reuse a heap what is not surely empty you |
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580 | /// should first clear the heap and after that you should set the |
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581 | /// cross reference map for each item to \c PRE_HEAP. |
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582 | void clear() { |
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583 | data.clear(); first.clear(); free = -1; num = 0; minimal = 0; |
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584 | } |
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585 | |
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586 | /// \brief Insert a pair of item and priority into the heap. |
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587 | /// |
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588 | /// Adds \c p.first to the heap with priority \c p.second. |
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589 | /// \param p The pair to insert. |
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590 | void push(const Pair& p) { |
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591 | push(p.first, p.second); |
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592 | } |
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593 | |
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594 | /// \brief Insert an item into the heap with the given priority. |
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595 | /// |
---|
596 | /// Adds \c i to the heap with priority \c p. |
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597 | /// \param i The item to insert. |
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598 | /// \param p The priority of the item. |
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599 | void push(const Item &i, const Prio &p) { |
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600 | int idx; |
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601 | if (free == -1) { |
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602 | idx = data.size(); |
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603 | data.push_back(BucketItem(i)); |
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604 | } else { |
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605 | idx = free; |
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606 | free = data[idx].next; |
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607 | data[idx].item = i; |
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608 | } |
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609 | index[i] = idx; |
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610 | if (p >= int(first.size())) first.resize(p + 1, -1); |
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611 | data[idx].next = first[p]; |
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612 | first[p] = idx; |
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613 | if (p < minimal) { |
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614 | minimal = p; |
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615 | } |
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616 | ++num; |
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617 | } |
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618 | |
---|
619 | /// \brief Returns the item with minimum priority. |
---|
620 | /// |
---|
621 | /// This method returns the item with minimum priority. |
---|
622 | /// \pre The heap must be nonempty. |
---|
623 | Item top() const { |
---|
624 | while (first[minimal] == -1) { |
---|
625 | ++minimal; |
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626 | } |
---|
627 | return data[first[minimal]].item; |
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628 | } |
---|
629 | |
---|
630 | /// \brief Returns the minimum priority. |
---|
631 | /// |
---|
632 | /// It returns the minimum priority. |
---|
633 | /// \pre The heap must be nonempty. |
---|
634 | Prio prio() const { |
---|
635 | while (first[minimal] == -1) { |
---|
636 | ++minimal; |
---|
637 | } |
---|
638 | return minimal; |
---|
639 | } |
---|
640 | |
---|
641 | /// \brief Deletes the item with minimum priority. |
---|
642 | /// |
---|
643 | /// This method deletes the item with minimum priority from the heap. |
---|
644 | /// \pre The heap must be non-empty. |
---|
645 | void pop() { |
---|
646 | while (first[minimal] == -1) { |
---|
647 | ++minimal; |
---|
648 | } |
---|
649 | int idx = first[minimal]; |
---|
650 | index[data[idx].item] = -2; |
---|
651 | first[minimal] = data[idx].next; |
---|
652 | data[idx].next = free; |
---|
653 | free = idx; |
---|
654 | --num; |
---|
655 | } |
---|
656 | |
---|
657 | /// \brief Returns the priority of \c i. |
---|
658 | /// |
---|
659 | /// This function returns the priority of item \c i. |
---|
660 | /// \warning This operator is not a constant time function |
---|
661 | /// because it scans the whole data structure to find the proper |
---|
662 | /// value. |
---|
663 | /// \pre \c i must be in the heap. |
---|
664 | /// \param i The item. |
---|
665 | Prio operator[](const Item &i) const { |
---|
666 | for (int k = 0; k < first.size(); ++k) { |
---|
667 | int idx = first[k]; |
---|
668 | while (idx != -1) { |
---|
669 | if (data[idx].item == i) { |
---|
670 | return k; |
---|
671 | } |
---|
672 | idx = data[idx].next; |
---|
673 | } |
---|
674 | } |
---|
675 | return -1; |
---|
676 | } |
---|
677 | |
---|
678 | /// \brief Returns if \c item is in, has already been in, or has |
---|
679 | /// never been in the heap. |
---|
680 | /// |
---|
681 | /// This method returns PRE_HEAP if \c item has never been in the |
---|
682 | /// heap, IN_HEAP if it is in the heap at the moment, and POST_HEAP |
---|
683 | /// otherwise. In the latter case it is possible that \c item will |
---|
684 | /// get back to the heap again. |
---|
685 | /// \param i The item. |
---|
686 | state_enum state(const Item &i) const { |
---|
687 | int idx = index[i]; |
---|
688 | if (idx >= 0) idx = 0; |
---|
689 | return state_enum(idx); |
---|
690 | } |
---|
691 | |
---|
692 | private: |
---|
693 | |
---|
694 | struct BucketItem { |
---|
695 | BucketItem(const Item& _item) |
---|
696 | : item(_item) {} |
---|
697 | |
---|
698 | Item item; |
---|
699 | int next; |
---|
700 | }; |
---|
701 | |
---|
702 | ItemIntMap& index; |
---|
703 | std::vector<int> first; |
---|
704 | std::vector<BucketItem> data; |
---|
705 | int free, num; |
---|
706 | mutable int minimal; |
---|
707 | |
---|
708 | }; // class SimpleBucketHeap |
---|
709 | |
---|
710 | template <typename _ItemIntMap> |
---|
711 | class SimpleBucketHeap<_ItemIntMap, false> { |
---|
712 | |
---|
713 | public: |
---|
714 | typedef typename _ItemIntMap::Key Item; |
---|
715 | typedef int Prio; |
---|
716 | typedef std::pair<Item, Prio> Pair; |
---|
717 | typedef _ItemIntMap ItemIntMap; |
---|
718 | |
---|
719 | enum state_enum { |
---|
720 | IN_HEAP = 0, |
---|
721 | PRE_HEAP = -1, |
---|
722 | POST_HEAP = -2 |
---|
723 | }; |
---|
724 | |
---|
725 | public: |
---|
726 | |
---|
727 | explicit SimpleBucketHeap(ItemIntMap &_index) |
---|
728 | : index(_index), free(-1), num(0), maximal(0) {} |
---|
729 | |
---|
730 | int size() const { return num; } |
---|
731 | |
---|
732 | bool empty() const { return num == 0; } |
---|
733 | |
---|
734 | void clear() { |
---|
735 | data.clear(); first.clear(); free = -1; num = 0; maximal = 0; |
---|
736 | } |
---|
737 | |
---|
738 | void push(const Pair& p) { |
---|
739 | push(p.first, p.second); |
---|
740 | } |
---|
741 | |
---|
742 | void push(const Item &i, const Prio &p) { |
---|
743 | int idx; |
---|
744 | if (free == -1) { |
---|
745 | idx = data.size(); |
---|
746 | data.push_back(BucketItem(i)); |
---|
747 | } else { |
---|
748 | idx = free; |
---|
749 | free = data[idx].next; |
---|
750 | data[idx].item = i; |
---|
751 | } |
---|
752 | index[i] = idx; |
---|
753 | if (p >= int(first.size())) first.resize(p + 1, -1); |
---|
754 | data[idx].next = first[p]; |
---|
755 | first[p] = idx; |
---|
756 | if (p > maximal) { |
---|
757 | maximal = p; |
---|
758 | } |
---|
759 | ++num; |
---|
760 | } |
---|
761 | |
---|
762 | Item top() const { |
---|
763 | while (first[maximal] == -1) { |
---|
764 | --maximal; |
---|
765 | } |
---|
766 | return data[first[maximal]].item; |
---|
767 | } |
---|
768 | |
---|
769 | Prio prio() const { |
---|
770 | while (first[maximal] == -1) { |
---|
771 | --maximal; |
---|
772 | } |
---|
773 | return maximal; |
---|
774 | } |
---|
775 | |
---|
776 | void pop() { |
---|
777 | while (first[maximal] == -1) { |
---|
778 | --maximal; |
---|
779 | } |
---|
780 | int idx = first[maximal]; |
---|
781 | index[data[idx].item] = -2; |
---|
782 | first[maximal] = data[idx].next; |
---|
783 | data[idx].next = free; |
---|
784 | free = idx; |
---|
785 | --num; |
---|
786 | } |
---|
787 | |
---|
788 | Prio operator[](const Item &i) const { |
---|
789 | for (int k = 0; k < first.size(); ++k) { |
---|
790 | int idx = first[k]; |
---|
791 | while (idx != -1) { |
---|
792 | if (data[idx].item == i) { |
---|
793 | return k; |
---|
794 | } |
---|
795 | idx = data[idx].next; |
---|
796 | } |
---|
797 | } |
---|
798 | return -1; |
---|
799 | } |
---|
800 | |
---|
801 | state_enum state(const Item &i) const { |
---|
802 | int idx = index[i]; |
---|
803 | if (idx >= 0) idx = 0; |
---|
804 | return state_enum(idx); |
---|
805 | } |
---|
806 | |
---|
807 | private: |
---|
808 | |
---|
809 | struct BucketItem { |
---|
810 | BucketItem(const Item& _item) : item(_item) {} |
---|
811 | |
---|
812 | Item item; |
---|
813 | |
---|
814 | int next; |
---|
815 | }; |
---|
816 | |
---|
817 | ItemIntMap& index; |
---|
818 | std::vector<int> first; |
---|
819 | std::vector<BucketItem> data; |
---|
820 | int free, num; |
---|
821 | mutable int maximal; |
---|
822 | |
---|
823 | }; |
---|
824 | |
---|
825 | } |
---|
826 | |
---|
827 | #endif |
---|