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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) 2003-2006 |
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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_BITS_LP_SOLVER_ID_H |
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20 #define LEMON_BITS_LP_SOLVER_ID_H |
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21 |
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22 namespace lemon { |
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23 |
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24 namespace _lp_bits { |
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25 |
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26 struct LpIdImpl { |
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27 std::vector<int> index; |
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28 std::vector<int> cross; |
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29 int first_index; |
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30 int first_free; |
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31 }; |
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32 |
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33 class LpId { |
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34 public: |
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35 |
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36 class IdHandler { |
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37 public: |
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38 virtual ~IdHandler() {} |
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39 virtual int addId(LpIdImpl&) = 0; |
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40 virtual void eraseId(LpIdImpl&, int xn) = 0; |
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41 }; |
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42 |
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43 LpId(int min_index = 0) { |
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44 id_handler = 0; |
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45 impl.first_free = -1; |
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46 impl.first_index = min_index; |
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47 impl.cross.resize(impl.first_index); |
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48 } |
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49 |
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50 void setIdHandler(IdHandler& ih) { |
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51 id_handler = &ih; |
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52 } |
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53 |
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54 int fixId(int fn) const {return impl.cross[fn];} |
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55 int floatingId(int xn) const {return impl.index[xn];} |
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56 |
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57 int addId() { |
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58 if (id_handler == 0) { |
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59 int xn, fn = impl.cross.size(); |
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60 if (impl.first_free == -1) { |
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61 xn = impl.index.size(); |
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62 impl.index.push_back(fn); |
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63 } else { |
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64 xn = impl.first_free; |
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65 impl.first_free = impl.index[impl.first_free]; |
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66 impl.index[xn] = fn; |
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67 } |
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68 impl.cross.push_back(xn); |
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69 return xn; |
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70 } else { |
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71 return id_handler->addId(impl); |
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72 } |
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73 } |
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74 |
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75 void eraseId(int xn) { |
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76 if (id_handler == 0) { |
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77 int fn = impl.index[xn]; |
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78 impl.index[xn] = impl.first_free; |
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79 impl.first_free = xn; |
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80 for(int i = fn + 1; i < (int)impl.cross.size(); ++i) { |
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81 impl.cross[i - 1] = impl.cross[i]; |
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82 impl.index[impl.cross[i]]--; |
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83 } |
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84 impl.cross.pop_back(); |
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85 } else { |
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86 id_handler->eraseId(impl, xn); |
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87 } |
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88 } |
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89 |
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90 void firstFloating(int& fn) const { |
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91 fn = impl.first_index; |
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92 if (fn == (int)impl.cross.size()) fn = -1; |
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93 } |
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94 |
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95 void nextFloating(int& fn) const { |
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96 ++fn; |
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97 if (fn == (int)impl.cross.size()) fn = -1; |
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98 } |
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99 |
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100 void firstFix(int& xn) const { |
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101 int fn; |
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102 firstFloating(fn); |
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103 xn = fn != -1 ? fixId(fn) : -1; |
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104 } |
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105 |
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106 void nextFix(int& xn) const { |
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107 int fn = floatingId(xn); |
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108 nextFloating(fn); |
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109 xn = fn != -1 ? fixId(fn) : -1; |
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110 } |
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111 |
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112 protected: |
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113 LpIdImpl impl; |
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114 IdHandler *id_handler; |
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115 }; |
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116 |
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117 class RelocateIdHandler : public LpId::IdHandler { |
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118 public: |
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119 |
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120 virtual int addId(LpIdImpl& impl) { |
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121 int xn, fn = impl.cross.size(); |
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122 if (impl.first_free == -1) { |
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123 xn = impl.index.size(); |
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124 impl.index.push_back(fn); |
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125 } else { |
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126 xn = impl.first_free; |
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127 impl.first_free = impl.index[impl.first_free]; |
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128 impl.index[xn] = fn; |
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129 } |
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130 impl.cross.push_back(xn); |
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131 return xn; |
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132 } |
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133 |
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134 virtual void eraseId(LpIdImpl& impl, int xn) { |
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135 int fn = impl.index[xn]; |
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136 impl.index[xn] = impl.first_free; |
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137 impl.first_free = xn; |
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138 impl.cross[fn] = impl.cross.back(); |
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139 impl.index[impl.cross.back()] = fn; |
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140 impl.cross.pop_back(); |
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141 } |
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142 }; |
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143 } |
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144 } |
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145 |
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146 #endif |