[481] | 1 | /* -*- mode: C++; indent-tabs-mode: nil; -*- |
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| 2 | * |
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| 3 | * This file is a part of LEMON, a generic C++ optimization library. |
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| 4 | * |
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| 5 | * Copyright (C) 2003-2008 |
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| 6 | * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
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| 7 | * (Egervary Research Group on Combinatorial Optimization, EGRES). |
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| 8 | * |
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| 9 | * Permission to use, modify and distribute this software is granted |
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| 10 | * provided that this copyright notice appears in all copies. For |
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| 11 | * precise terms see the accompanying LICENSE file. |
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| 12 | * |
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| 13 | * This software is provided "AS IS" with no warranty of any kind, |
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| 14 | * express or implied, and with no claim as to its suitability for any |
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| 15 | * purpose. |
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| 16 | * |
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| 17 | */ |
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| 18 | |
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| 19 | #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 | LpId(const LpId& li) { |
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| 51 | id_handler = 0; |
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| 52 | impl = li.impl; |
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| 53 | } |
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| 54 | |
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| 55 | LpId& operator=(const LpId& li) { |
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| 56 | id_handler = 0; |
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| 57 | impl = li.impl; |
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| 58 | return *this; |
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| 59 | } |
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| 60 | |
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| 61 | void setIdHandler(IdHandler& ih) { |
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| 62 | id_handler = &ih; |
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| 63 | } |
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| 64 | |
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| 65 | int fixId(int fn) const {return impl.cross[fn];} |
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| 66 | int floatingId(int xn) const {return impl.index[xn];} |
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| 67 | |
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| 68 | int addId() { |
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| 69 | if (id_handler == 0) { |
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| 70 | int xn, fn = impl.cross.size(); |
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| 71 | if (impl.first_free == -1) { |
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| 72 | xn = impl.index.size(); |
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| 73 | impl.index.push_back(fn); |
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| 74 | } else { |
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| 75 | xn = impl.first_free; |
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| 76 | impl.first_free = impl.index[impl.first_free]; |
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| 77 | impl.index[xn] = fn; |
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| 78 | } |
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| 79 | impl.cross.push_back(xn); |
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| 80 | return xn; |
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| 81 | } else { |
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| 82 | return id_handler->addId(impl); |
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| 83 | } |
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| 84 | } |
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| 85 | |
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| 86 | void eraseId(int xn) { |
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| 87 | if (id_handler == 0) { |
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| 88 | int fn = impl.index[xn]; |
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| 89 | impl.index[xn] = impl.first_free; |
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| 90 | impl.first_free = xn; |
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| 91 | for(int i = fn + 1; i < int(impl.cross.size()); ++i) { |
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| 92 | impl.cross[i - 1] = impl.cross[i]; |
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| 93 | impl.index[impl.cross[i]]--; |
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| 94 | } |
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| 95 | impl.cross.pop_back(); |
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| 96 | } else { |
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| 97 | id_handler->eraseId(impl, xn); |
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| 98 | } |
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| 99 | } |
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| 100 | |
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| 101 | void firstFloating(int& fn) const { |
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| 102 | fn = impl.first_index; |
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| 103 | if (fn == int(impl.cross.size())) fn = -1; |
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| 104 | } |
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| 105 | |
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| 106 | void nextFloating(int& fn) const { |
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| 107 | ++fn; |
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| 108 | if (fn == int(impl.cross.size())) fn = -1; |
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| 109 | } |
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| 110 | |
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| 111 | void firstFix(int& xn) const { |
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| 112 | int fn; |
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| 113 | firstFloating(fn); |
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| 114 | xn = fn != -1 ? fixId(fn) : -1; |
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| 115 | } |
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| 116 | |
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| 117 | void nextFix(int& xn) const { |
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| 118 | int fn = floatingId(xn); |
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| 119 | nextFloating(fn); |
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| 120 | xn = fn != -1 ? fixId(fn) : -1; |
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| 121 | } |
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| 122 | |
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| 123 | protected: |
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| 124 | LpIdImpl impl; |
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| 125 | IdHandler *id_handler; |
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| 126 | }; |
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| 127 | |
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| 128 | class RelocateIdHandler : public LpId::IdHandler { |
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| 129 | public: |
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| 130 | |
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| 131 | virtual int addId(LpIdImpl& impl) { |
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| 132 | int xn, fn = impl.cross.size(); |
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| 133 | if (impl.first_free == -1) { |
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| 134 | xn = impl.index.size(); |
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| 135 | impl.index.push_back(fn); |
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| 136 | } else { |
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| 137 | xn = impl.first_free; |
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| 138 | impl.first_free = impl.index[impl.first_free]; |
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| 139 | impl.index[xn] = fn; |
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| 140 | } |
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| 141 | impl.cross.push_back(xn); |
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| 142 | return xn; |
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| 143 | } |
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| 144 | |
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| 145 | virtual void eraseId(LpIdImpl& impl, int xn) { |
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| 146 | int fn = impl.index[xn]; |
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| 147 | impl.index[xn] = impl.first_free; |
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| 148 | impl.first_free = xn; |
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| 149 | impl.cross[fn] = impl.cross.back(); |
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| 150 | impl.index[impl.cross.back()] = fn; |
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| 151 | impl.cross.pop_back(); |
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| 152 | } |
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| 153 | }; |
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| 154 | } |
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| 155 | } |
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| 156 | |
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| 157 | #endif |
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