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 |
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