[2316] | 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_LP_UTILS_H |
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| 20 | #define LEMON_LP_UTILS_H |
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| 21 | |
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| 22 | #include <lemon/lp_base.h> |
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| 23 | |
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| 24 | #include <lemon/lemon_reader.h> |
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[2363] | 25 | #include <lemon/lemon_writer.h> |
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[2316] | 26 | |
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[2368] | 27 | #include <map> |
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| 28 | #include <set> |
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| 29 | |
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| 30 | |
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[2316] | 31 | namespace lemon { |
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| 32 | |
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[2368] | 33 | /// \ingroup gen_opt_tools |
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| 34 | /// |
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| 35 | /// \brief The map for the result of the lp variables. |
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| 36 | /// |
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| 37 | /// The map for the result of the lp variables. |
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| 38 | class LpResultMap { |
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| 39 | public: |
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| 40 | typedef LpSolverBase::Col Key; |
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| 41 | typedef LpSolverBase::Value Value; |
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| 42 | |
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| 43 | /// \brief Constructor |
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| 44 | /// |
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| 45 | /// Constructor |
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| 46 | LpResultMap(const LpSolverBase& _lp) : lp(_lp) {} |
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| 47 | LpSolverBase::Value operator[](const LpSolverBase::Col col) const { |
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| 48 | return lp.primal(col); |
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| 49 | } |
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| 50 | private: |
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| 51 | const LpSolverBase& lp; |
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| 52 | }; |
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| 53 | |
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| 54 | /// \ingroup gen_opt_tools |
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| 55 | /// |
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| 56 | /// \brief The map for the name of the lp variables. |
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| 57 | /// |
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| 58 | /// The map for the name of the lp variables. |
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| 59 | class LpColNameMap { |
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| 60 | public: |
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| 61 | typedef LpSolverBase::Col Key; |
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| 62 | typedef std::string Value; |
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| 63 | |
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| 64 | /// \brief Constructor |
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| 65 | /// |
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| 66 | /// Constructor |
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| 67 | LpColNameMap(const LpSolverBase& _lp) : lp(_lp) {} |
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| 68 | std::string operator[](const LpSolverBase::Col col) const { |
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| 69 | return lp.colName(col); |
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| 70 | } |
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| 71 | private: |
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| 72 | const LpSolverBase& lp; |
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| 73 | }; |
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| 74 | |
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| 75 | /// \ingroup gen_opt_tools |
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| 76 | /// |
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| 77 | /// \brief Writeable map for the name of the lp variables. |
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| 78 | /// |
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| 79 | /// Writeable map for the name of the lp variables. |
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| 80 | class LpColNameWriteMap { |
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| 81 | public: |
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| 82 | typedef LpSolverBase::Col Key; |
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| 83 | typedef std::string Value; |
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| 84 | |
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| 85 | /// \brief Constructor |
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| 86 | /// |
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| 87 | /// Constructor |
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| 88 | LpColNameWriteMap(LpSolverBase& _lp) : lp(_lp) {} |
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| 89 | std::string operator[](const LpSolverBase::Col col) const { |
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| 90 | return lp.colName(col); |
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| 91 | } |
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| 92 | void set(const LpSolverBase::Col col, const std::string& name) { |
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| 93 | lp.colName(col, name); |
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| 94 | } |
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| 95 | private: |
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| 96 | LpSolverBase& lp; |
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| 97 | }; |
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| 98 | |
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| 99 | /// \ingroup gen_opt_tools |
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| 100 | /// |
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| 101 | /// \brief Returns an \ref LpColNameMap class |
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| 102 | /// |
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| 103 | /// This function just returns an \ref LpColNameMap class. |
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| 104 | /// \relates LpColNameMap |
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| 105 | LpColNameMap lpColNameMap(const LpSolverBase& lp) { |
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| 106 | return LpColNameMap(lp); |
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| 107 | } |
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| 108 | |
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| 109 | LpColNameWriteMap lpColNameMap(LpSolverBase& lp) { |
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| 110 | return LpColNameWriteMap(lp); |
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| 111 | } |
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| 112 | |
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| 113 | /// \ingroup gen_opt_tools |
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| 114 | /// |
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| 115 | /// \brief Lp variable item reader for Lemon IO |
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| 116 | /// |
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| 117 | /// This class is an Lp variable item reader for Lemon IO. It makes |
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| 118 | /// possible to store lp variables in lemon file. The usage of this |
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| 119 | /// class is very simple: |
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| 120 | /// |
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| 121 | ///\code |
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| 122 | /// Graph graph; |
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| 123 | /// Lp lp; |
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| 124 | /// Graph::EdgeMap<Lp::Col> var(graph); |
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| 125 | /// |
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| 126 | /// GraphReader<Graph> reader(cin, graph); |
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| 127 | /// reader.readEdgeMap("lpvar", var, LpColReader(lp)); |
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| 128 | /// reader.run(); |
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| 129 | ///\endcode |
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| 130 | /// |
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| 131 | /// If there is already a variable with the same name in the lp then |
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| 132 | /// it will be used for the return value. If there is no such variable |
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| 133 | /// then it will be constructed. The file could contain \c '-' as value |
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| 134 | /// which means that no lp variable associated to the current item and |
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| 135 | /// in this case INVALID will be returned. |
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| 136 | class LpColReader { |
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| 137 | public: |
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| 138 | |
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| 139 | /// \brief The value type of reader. |
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| 140 | /// |
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| 141 | /// The value type of reader. |
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| 142 | typedef LpSolverBase::Col Value; |
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| 143 | |
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| 144 | /// \brief Constructor for the reader. |
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| 145 | /// |
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| 146 | /// Constructor for the reader. |
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| 147 | LpColReader(LpSolverBase& _lp) : lp(_lp) {} |
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| 148 | |
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| 149 | /// \brief Reads an lp variable from the given stream. |
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| 150 | /// |
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| 151 | /// Reads an lp variable string from the given stream. |
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| 152 | void read(std::istream& is, LpSolverBase::Col& col) const { |
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| 153 | char x; |
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| 154 | is >> std::ws; |
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| 155 | if (!is.get(x)) |
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| 156 | throw DataFormatError("Wrong Lp Column format!"); |
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| 157 | if (varFirstChar(x)) { |
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| 158 | std::string var; |
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| 159 | var += x; |
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| 160 | |
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| 161 | while (is.get(x) && varChar(x)) { |
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| 162 | var += x; |
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| 163 | } |
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| 164 | if (!is) { |
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| 165 | is.clear(); |
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| 166 | } else { |
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| 167 | is.putback(x); |
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| 168 | } |
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| 169 | col = lp.colByName(var); |
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| 170 | if (col == INVALID) { |
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| 171 | col = lp.addCol(); |
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| 172 | lp.colName(col, var); |
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| 173 | } |
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| 174 | } else if (x == '-') { |
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| 175 | col = INVALID; |
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| 176 | is >> std::ws; |
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| 177 | } else { |
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| 178 | std::cerr << x << std::endl; |
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| 179 | throw DataFormatError("Wrong Lp Column format"); |
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| 180 | } |
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| 181 | } |
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| 182 | |
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| 183 | private: |
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| 184 | |
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| 185 | static bool varFirstChar(char c) { |
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| 186 | return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z'); |
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| 187 | } |
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| 188 | |
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| 189 | static bool varChar(char c) { |
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| 190 | return (c >= '0' && c <= '9') || |
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| 191 | (c >= 'a' && c <= 'z') || |
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| 192 | (c >= 'A' && c <= 'Z') || |
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| 193 | c == '[' || c == ']'; |
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| 194 | } |
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| 195 | |
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| 196 | LpSolverBase& lp; |
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| 197 | |
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| 198 | }; |
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| 199 | |
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| 200 | /// \ingroup gen_opt_tools |
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| 201 | /// |
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| 202 | /// \brief Lp variable item writer for Lemon IO |
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| 203 | /// |
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| 204 | /// This class is an Lp variable item writer for Lemon IO. It makes |
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| 205 | /// possible to store lp variables in lemon file. The usage of this |
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| 206 | /// class is very simple: |
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| 207 | /// |
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| 208 | ///\code |
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| 209 | /// Graph graph; |
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| 210 | /// Lp lp; |
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| 211 | /// Graph::EdgeMap<Lp::Col> var(graph); |
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| 212 | /// |
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| 213 | /// GraphWriter<Graph> writer(cin, graph); |
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| 214 | /// writer.writeEdgeMap("lpvar", var, LpColWriter(lp)); |
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| 215 | /// writer.run(); |
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| 216 | ///\endcode |
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| 217 | /// |
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| 218 | /// If there is no name associated to the current item then the name |
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| 219 | /// will automatically constructed. If the value is INVALID then it |
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| 220 | /// will write an \c '-' value to the file. |
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| 221 | class LpColWriter { |
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| 222 | public: |
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| 223 | |
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| 224 | /// \brief The value type of writer. |
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| 225 | /// |
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| 226 | /// The value type of writer. |
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| 227 | typedef LpSolverBase::Col Value; |
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| 228 | |
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| 229 | /// \brief Constructor for the writer. |
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| 230 | /// |
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| 231 | /// Constructor for the writer. |
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| 232 | LpColWriter(const LpSolverBase& _lp) : lp(_lp), num(0) {} |
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| 233 | |
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| 234 | /// \brief Writes an lp variable to the given stream. |
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| 235 | /// |
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| 236 | /// Writes an lp variable to the given stream. |
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| 237 | void write(std::ostream& os, const LpSolverBase::Col& col) const { |
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| 238 | if (col != INVALID) { |
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| 239 | std::string name = lp.colName(col); |
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| 240 | if (name.empty()) { |
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| 241 | std::ostringstream ls; |
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| 242 | ls << "x" << num; |
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| 243 | ++num; |
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| 244 | while (lp.colByName(ls.str()) != INVALID) { |
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| 245 | ls.str(std::string()); |
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| 246 | ls << "x" << num; |
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| 247 | ++num; |
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| 248 | } |
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| 249 | const_cast<LpSolverBase&>(lp).colName(col, ls.str()); |
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| 250 | os << ls.str(); |
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| 251 | } else { |
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| 252 | os << name; |
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| 253 | } |
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| 254 | } else { |
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| 255 | os << "-"; |
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| 256 | } |
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| 257 | } |
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| 258 | |
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| 259 | private: |
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| 260 | |
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| 261 | const LpSolverBase& lp; |
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| 262 | mutable int num; |
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| 263 | |
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| 264 | }; |
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| 265 | |
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| 266 | /// \ingroup gen_opt_tools |
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| 267 | /// |
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| 268 | /// \brief Lp section reader for lemon IO |
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| 269 | /// |
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| 270 | /// This section reader provides an easy way to read an Lp problem |
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| 271 | /// from a file. The lemon lp section format contains three parts. |
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| 272 | /// |
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| 273 | ///\code |
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| 274 | /// @lp |
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| 275 | /// constraints |
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| 276 | /// 7 == x1 - 1 * x2 |
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| 277 | /// 2 * x1 + x3 / 2 <= 7 |
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| 278 | /// x2 + -3 * x3 >= 8 |
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| 279 | /// 3 <= x2 - 2 * x1 <= 8 |
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| 280 | /// bounds |
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| 281 | /// x1 >= 3 |
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| 282 | /// 2 <= x2 <= 5 |
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| 283 | /// 0 <= x3 <= 8 |
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| 284 | /// objective |
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| 285 | /// min x1 + 2 * x2 - x3 |
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| 286 | ///\endcode |
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| 287 | /// |
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| 288 | /// The first part gives the constraints to the lp. The constraints |
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| 289 | /// could be equality, lower bound, upper bound or range for an |
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| 290 | /// expression or equality, less or more for two expressions. |
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| 291 | /// |
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| 292 | /// The second part gives the bounds for the variables. The bounds |
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| 293 | /// could be the same as for the single expression so equality, |
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| 294 | /// lower bound, upper bound or range. |
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| 295 | /// |
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| 296 | /// The third part is the objective function, it should start with |
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| 297 | /// \c min or \c max and then a valid linear expression. |
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| 298 | /// |
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| 299 | /// The reader constructs automatically the variable for a name if |
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| 300 | /// there is not already a variable with the same name. |
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| 301 | /// |
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| 302 | /// The basic way to read an LP problem is made by the next code: |
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| 303 | ///\code |
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| 304 | /// Lp lp; |
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| 305 | /// |
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| 306 | /// LemonReader reader(filename_or_istream); |
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| 307 | /// LpReader lpreader(reader, lp); |
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| 308 | /// |
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| 309 | /// reader.run(); |
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| 310 | ///\endcode |
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| 311 | /// |
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| 312 | /// Of course instead of \c LemonReader you can give a \c |
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| 313 | /// GraphReader to the LpReader constructor. Also useful that you |
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| 314 | /// can mix lp problems and graphs in the same file. |
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[2316] | 315 | class LpReader : public LemonReader::SectionReader { |
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| 316 | typedef LemonReader::SectionReader Parent; |
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| 317 | public: |
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| 318 | |
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| 319 | |
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| 320 | /// \brief Constructor. |
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| 321 | /// |
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[2368] | 322 | /// Constructor for LpReader. It creates the LpReader and attachs |
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[2316] | 323 | /// it into the given LemonReader. The lp reader will add |
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| 324 | /// variables, constraints and objective function to the |
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| 325 | /// given lp solver. |
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| 326 | LpReader(LemonReader& _reader, LpSolverBase& _lp, |
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| 327 | const std::string& _name = std::string()) |
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| 328 | : Parent(_reader), lp(_lp), name(_name) {} |
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| 329 | |
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| 330 | |
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| 331 | /// \brief Destructor. |
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| 332 | /// |
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[2368] | 333 | /// Destructor for LpReader. |
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[2316] | 334 | virtual ~LpReader() {} |
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| 335 | |
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| 336 | private: |
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| 337 | LpReader(const LpReader&); |
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| 338 | void operator=(const LpReader&); |
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| 339 | |
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| 340 | protected: |
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| 341 | |
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| 342 | /// \brief Gives back true when the SectionReader can process |
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| 343 | /// the section with the given header line. |
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| 344 | /// |
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| 345 | /// It gives back true when the header line starts with \c \@lp, |
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| 346 | /// and the header line's name and the nodeset's name are the same. |
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| 347 | virtual bool header(const std::string& line) { |
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| 348 | std::istringstream ls(line); |
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| 349 | std::string command; |
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| 350 | std::string id; |
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| 351 | ls >> command >> id; |
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| 352 | return command == "@lp" && name == id; |
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| 353 | } |
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| 354 | |
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| 355 | private: |
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| 356 | |
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[2368] | 357 | enum Part { |
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[2364] | 358 | CONSTRAINTS, BOUNDS, OBJECTIVE |
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| 359 | }; |
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| 360 | |
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[2316] | 361 | enum Relation { |
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| 362 | LE, EQ, GE |
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| 363 | }; |
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| 364 | |
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[2364] | 365 | std::istream& readConstraint(std::istream& is) { |
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| 366 | LpSolverBase::Constr c; |
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[2316] | 367 | char x; |
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| 368 | LpSolverBase::Expr e1, e2; |
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| 369 | Relation op1; |
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| 370 | is >> std::ws; |
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| 371 | readExpression(is, e1); |
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| 372 | is >> std::ws; |
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| 373 | readRelation(is, op1); |
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| 374 | is >> std::ws; |
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| 375 | readExpression(is, e2); |
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[2364] | 376 | is >> std::ws; |
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[2316] | 377 | if (!is.get(x)) { |
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| 378 | if (op1 == LE) { |
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[2364] | 379 | if (e1.size() == 0) { |
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| 380 | c = e2 >= e1; |
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| 381 | } else { |
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| 382 | c = e1 <= e2; |
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| 383 | } |
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[2316] | 384 | c = e1 <= e2; |
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| 385 | } else if (op1 == GE) { |
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[2364] | 386 | if (e1.size() == 0) { |
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| 387 | c = e2 <= e1; |
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| 388 | } else { |
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| 389 | c = e1 >= e2; |
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| 390 | } |
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[2316] | 391 | } else { |
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[2364] | 392 | if (e1.size() == 0) { |
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| 393 | c = e2 == e1; |
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| 394 | } else { |
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| 395 | c = e1 == e2; |
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| 396 | } |
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[2316] | 397 | } |
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| 398 | } else { |
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| 399 | is.putback(x); |
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| 400 | LpSolverBase::Expr e3; |
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| 401 | Relation op2; |
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| 402 | readRelation(is, op2); |
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| 403 | is >> std::ws; |
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| 404 | readExpression(is, e3); |
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| 405 | if (!e1.empty() || !e3.empty()) { |
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| 406 | throw DataFormatError("Wrong range format"); |
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| 407 | } |
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| 408 | if (op2 != op1 || op1 == EQ) { |
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| 409 | throw DataFormatError("Wrong range format"); |
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| 410 | } |
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| 411 | if (op1 == LE) { |
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| 412 | c = e1.constComp() <= e2 <= e3.constComp(); |
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| 413 | } else { |
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| 414 | c = e1.constComp() >= e2 >= e3.constComp(); |
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| 415 | } |
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[2364] | 416 | is >> std::ws; |
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| 417 | if (is.get(x)) { |
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| 418 | throw DataFormatError("Wrong variable bounds format"); |
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| 419 | } |
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[2316] | 420 | } |
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[2364] | 421 | lp.addRow(c); |
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| 422 | return is; |
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| 423 | } |
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| 424 | |
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| 425 | std::istream& readObjective(std::istream& is) { |
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| 426 | is >> std::ws; |
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| 427 | std::string sense; |
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| 428 | is >> sense; |
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| 429 | if (sense != "min" && sense != "max") { |
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| 430 | throw DataFormatError("Wrong objective function format"); |
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| 431 | } |
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| 432 | LpSolverBase::Expr expr; |
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| 433 | is >> std::ws; |
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| 434 | readExpression(is, expr); |
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| 435 | lp.setObj(expr); |
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| 436 | if (sense == "min") { |
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| 437 | lp.min(); |
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| 438 | } else { |
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| 439 | lp.max(); |
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| 440 | } |
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| 441 | return is; |
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| 442 | } |
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| 443 | |
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| 444 | std::istream& readBounds(std::istream& is) { |
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| 445 | LpSolverBase::Col c; |
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| 446 | char x; |
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| 447 | is >> std::ws; |
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| 448 | if (!is.get(x)) { |
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| 449 | throw DataFormatError("Wrong variable bounds format"); |
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| 450 | } |
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| 451 | if (varFirstChar(x)) { |
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| 452 | is.putback(x); |
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| 453 | readCol(is, c); |
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| 454 | is >> std::ws; |
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| 455 | Relation op1; |
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| 456 | readRelation(is, op1); |
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| 457 | double v; |
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| 458 | readNum(is, v); |
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| 459 | if (op1 == EQ) { |
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| 460 | lp.colLowerBound(c, v); |
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| 461 | lp.colUpperBound(c, v); |
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| 462 | } else if (op1 == LE) { |
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| 463 | lp.colUpperBound(c, v); |
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| 464 | } else { |
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| 465 | lp.colLowerBound(c, v); |
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| 466 | } |
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| 467 | is >> std::ws; |
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| 468 | if (is.get(x)) { |
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| 469 | throw DataFormatError("Wrong variable bounds format"); |
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| 470 | } |
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| 471 | } else { |
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| 472 | is.putback(x); |
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| 473 | double v; |
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| 474 | readNum(is, v); |
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| 475 | is >> std::ws; |
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| 476 | Relation op1; |
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| 477 | readRelation(is, op1); |
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| 478 | is >> std::ws; |
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| 479 | readCol(is, c); |
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| 480 | is >> std::ws; |
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| 481 | if (is.get(x)) { |
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| 482 | is.putback(x); |
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| 483 | is >> std::ws; |
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| 484 | Relation op2; |
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| 485 | readRelation(is, op2); |
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| 486 | double w; |
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| 487 | is >> std::ws; |
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| 488 | readNum(is, w); |
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| 489 | if (op2 != op1 || op1 == EQ) { |
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| 490 | throw DataFormatError("Wrong range format"); |
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| 491 | } |
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| 492 | if (op1 == LE) { |
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| 493 | lp.colLowerBound(c, v); |
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| 494 | lp.colUpperBound(c, w); |
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| 495 | } else { |
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| 496 | lp.colLowerBound(c, w); |
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| 497 | lp.colUpperBound(c, v); |
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| 498 | } |
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[2368] | 499 | is >> std::ws; |
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[2364] | 500 | if (is.get(x)) { |
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| 501 | throw DataFormatError("Wrong variable bounds format"); |
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| 502 | } |
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| 503 | } else { |
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| 504 | if (op1 == EQ) { |
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| 505 | lp.colLowerBound(c, v); |
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| 506 | lp.colUpperBound(c, v); |
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| 507 | } else if (op1 == LE) { |
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| 508 | lp.colLowerBound(c, v); |
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| 509 | } else { |
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| 510 | lp.colUpperBound(c, v); |
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| 511 | } |
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| 512 | } |
---|
| 513 | } |
---|
| 514 | return is; |
---|
[2316] | 515 | } |
---|
| 516 | |
---|
| 517 | std::istream& readExpression(std::istream& is, LpSolverBase::Expr& e) { |
---|
| 518 | LpSolverBase::Col c; |
---|
| 519 | double d; |
---|
| 520 | char x; |
---|
| 521 | readElement(is, c, d); |
---|
| 522 | if (c != INVALID) { |
---|
| 523 | e += d * c; |
---|
| 524 | } else { |
---|
| 525 | e += d; |
---|
| 526 | } |
---|
| 527 | is >> std::ws; |
---|
| 528 | while (is.get(x) && (x == '+' || x == '-')) { |
---|
| 529 | is >> std::ws; |
---|
| 530 | readElement(is, c, d); |
---|
| 531 | if (c != INVALID) { |
---|
| 532 | e += (x == '+' ? d : -d) * c; |
---|
| 533 | } else { |
---|
| 534 | e += (x == '+' ? d : -d); |
---|
| 535 | } |
---|
| 536 | is >> std::ws; |
---|
| 537 | } |
---|
| 538 | if (!is) { |
---|
| 539 | is.clear(); |
---|
| 540 | } else { |
---|
| 541 | is.putback(x); |
---|
| 542 | } |
---|
| 543 | return is; |
---|
| 544 | } |
---|
| 545 | |
---|
| 546 | std::istream& readElement(std::istream& is, |
---|
| 547 | LpSolverBase::Col& c, double& d) { |
---|
| 548 | d = 1.0; |
---|
| 549 | c = INVALID; |
---|
| 550 | char x, y; |
---|
| 551 | if (!is.get(x)) throw DataFormatError("Cannot find lp element"); |
---|
| 552 | if (x == '+' || x == '-') { |
---|
| 553 | is >> std::ws; |
---|
| 554 | d *= x == '-' ? -1 : 1; |
---|
| 555 | while (is.get(x) && (x == '+' || x == '-')) { |
---|
| 556 | d *= x == '-' ? -1 : 1; |
---|
| 557 | is >> std::ws; |
---|
| 558 | } |
---|
| 559 | if (!is) throw DataFormatError("Cannot find lp element"); |
---|
| 560 | } |
---|
| 561 | if (numFirstChar(x)) { |
---|
| 562 | is.putback(x); |
---|
| 563 | double e; |
---|
| 564 | readNum(is, e); |
---|
| 565 | d *= e; |
---|
| 566 | } else if (varFirstChar(x)) { |
---|
| 567 | is.putback(x); |
---|
| 568 | LpSolverBase::Col f; |
---|
| 569 | readCol(is, f); |
---|
| 570 | c = f; |
---|
| 571 | } else { |
---|
| 572 | throw DataFormatError("Invalid expression format"); |
---|
| 573 | } |
---|
| 574 | is >> std::ws; |
---|
| 575 | while (is.get(y) && (y == '*' || y == '/')) { |
---|
| 576 | is >> std::ws; |
---|
| 577 | if (!is.get(x)) throw DataFormatError("Cannot find lp element"); |
---|
| 578 | if (x == '+' || x == '-') { |
---|
| 579 | is >> std::ws; |
---|
| 580 | d *= x == '-' ? -1 : 1; |
---|
| 581 | while (is.get(x) && (x == '+' || x == '-')) { |
---|
| 582 | d *= x == '-' ? -1 : 1; |
---|
| 583 | is >> std::ws; |
---|
| 584 | } |
---|
| 585 | if (!is) throw DataFormatError("Cannot find lp element"); |
---|
| 586 | } |
---|
| 587 | if (numFirstChar(x)) { |
---|
| 588 | is.putback(x); |
---|
| 589 | double e; |
---|
| 590 | readNum(is, e); |
---|
| 591 | if (y == '*') { |
---|
| 592 | d *= e; |
---|
| 593 | } else { |
---|
| 594 | d /= e; |
---|
| 595 | } |
---|
| 596 | } else if (varFirstChar(x)) { |
---|
| 597 | is.putback(x); |
---|
| 598 | LpSolverBase::Col f; |
---|
| 599 | readCol(is, f); |
---|
| 600 | if (y == '*') { |
---|
| 601 | if (c == INVALID) { |
---|
| 602 | c = f; |
---|
| 603 | } else { |
---|
| 604 | throw DataFormatError("Quadratic element in expression"); |
---|
| 605 | } |
---|
| 606 | } else { |
---|
| 607 | throw DataFormatError("Division by variable"); |
---|
| 608 | } |
---|
| 609 | } else { |
---|
| 610 | throw DataFormatError("Invalid expression format"); |
---|
| 611 | } |
---|
| 612 | is >> std::ws; |
---|
| 613 | } |
---|
| 614 | if (!is) { |
---|
| 615 | is.clear(); |
---|
| 616 | } else { |
---|
| 617 | is.putback(y); |
---|
| 618 | } |
---|
| 619 | return is; |
---|
| 620 | } |
---|
| 621 | |
---|
| 622 | std::istream& readCol(std::istream& is, LpSolverBase::Col& c) { |
---|
| 623 | char x; |
---|
| 624 | std::string var; |
---|
| 625 | while (is.get(x) && varChar(x)) { |
---|
| 626 | var += x; |
---|
| 627 | } |
---|
| 628 | if (!is) { |
---|
| 629 | is.clear(); |
---|
| 630 | } else { |
---|
| 631 | is.putback(x); |
---|
| 632 | } |
---|
[2368] | 633 | c = lp.colByName(var); |
---|
| 634 | if (c == INVALID) { |
---|
[2316] | 635 | c = lp.addCol(); |
---|
| 636 | lp.colName(c, var); |
---|
| 637 | } |
---|
| 638 | return is; |
---|
| 639 | } |
---|
| 640 | |
---|
| 641 | std::istream& readNum(std::istream& is, double& d) { |
---|
| 642 | is >> d; |
---|
| 643 | if (!is) throw DataFormatError("Wrong number format"); |
---|
| 644 | return is; |
---|
| 645 | } |
---|
| 646 | |
---|
| 647 | std::istream& readRelation(std::istream& is, Relation& op) { |
---|
| 648 | char x, y; |
---|
| 649 | if (!is.get(x) || !(x == '<' || x == '=' || x == '>')) { |
---|
| 650 | throw DataFormatError("Wrong relation operator"); |
---|
| 651 | } |
---|
| 652 | if (!is.get(y) || y != '=') { |
---|
| 653 | throw DataFormatError("Wrong relation operator"); |
---|
| 654 | } |
---|
| 655 | switch (x) { |
---|
| 656 | case '<': op = LE; |
---|
| 657 | break; |
---|
| 658 | case '=': op = EQ; |
---|
| 659 | break; |
---|
| 660 | case '>': op = GE; |
---|
| 661 | break; |
---|
| 662 | } |
---|
| 663 | return is; |
---|
| 664 | } |
---|
| 665 | |
---|
| 666 | static bool relationFirstChar(char c) { |
---|
| 667 | return c == '<' || c == '=' || c == '>'; |
---|
| 668 | } |
---|
| 669 | |
---|
| 670 | static bool varFirstChar(char c) { |
---|
| 671 | return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z'); |
---|
| 672 | } |
---|
| 673 | |
---|
| 674 | static bool numFirstChar(char c) { |
---|
| 675 | return (c >= '0' && c <= '9') || c == '.'; |
---|
| 676 | } |
---|
[2368] | 677 | |
---|
[2316] | 678 | static bool varChar(char c) { |
---|
| 679 | return (c >= '0' && c <= '9') || |
---|
[2364] | 680 | (c >= 'a' && c <= 'z') || |
---|
| 681 | (c >= 'A' && c <= 'Z') || |
---|
| 682 | c == '[' || c == ']'; |
---|
[2316] | 683 | } |
---|
| 684 | |
---|
| 685 | protected: |
---|
| 686 | |
---|
| 687 | /// \brief Reader function of the section. |
---|
| 688 | /// |
---|
| 689 | /// It reads the content of the section. |
---|
| 690 | virtual void read(std::istream& is) { |
---|
| 691 | std::string line; |
---|
[2368] | 692 | Part part = CONSTRAINTS; |
---|
[2316] | 693 | while (getline(is, line)) { |
---|
| 694 | std::istringstream ls(line); |
---|
[2364] | 695 | std::string type; |
---|
| 696 | ls >> type; |
---|
| 697 | if (type == "constraints") { |
---|
[2368] | 698 | part = CONSTRAINTS; |
---|
| 699 | ls >> std::ws; |
---|
| 700 | char x; |
---|
| 701 | if (ls.get(x)) |
---|
| 702 | throw DataFormatError("Wrong Lp format"); |
---|
[2364] | 703 | } else if (type == "bounds") { |
---|
[2368] | 704 | part = BOUNDS; |
---|
| 705 | ls >> std::ws; |
---|
| 706 | char x; |
---|
| 707 | if (ls.get(x)) |
---|
| 708 | throw DataFormatError("Wrong Lp format"); |
---|
[2364] | 709 | } else if (type == "objective") { |
---|
[2368] | 710 | part = OBJECTIVE; |
---|
| 711 | ls >> std::ws; |
---|
| 712 | char x; |
---|
| 713 | if (ls.get(x)) |
---|
| 714 | throw DataFormatError("Wrong Lp format"); |
---|
[2316] | 715 | } else { |
---|
| 716 | ls.str(line); |
---|
[2368] | 717 | switch (part) { |
---|
[2364] | 718 | case CONSTRAINTS: |
---|
| 719 | readConstraint(ls); |
---|
| 720 | break; |
---|
| 721 | case BOUNDS: |
---|
| 722 | readBounds(ls); |
---|
| 723 | break; |
---|
| 724 | case OBJECTIVE: |
---|
| 725 | readObjective(ls); |
---|
| 726 | break; |
---|
| 727 | } |
---|
[2368] | 728 | } |
---|
[2316] | 729 | } |
---|
| 730 | } |
---|
| 731 | |
---|
| 732 | virtual void missing() { |
---|
| 733 | ErrorMessage msg; |
---|
| 734 | msg << "Lp section not found in file: @lp " << name; |
---|
| 735 | throw IoParameterError(msg.message()); |
---|
| 736 | } |
---|
| 737 | |
---|
| 738 | private: |
---|
| 739 | |
---|
| 740 | |
---|
| 741 | LpSolverBase& lp; |
---|
| 742 | std::string name; |
---|
| 743 | }; |
---|
| 744 | |
---|
[2363] | 745 | |
---|
[2368] | 746 | /// \ingroup gen_opt_tools |
---|
| 747 | /// |
---|
| 748 | /// \brief Lp section writer for lemon IO |
---|
| 749 | /// |
---|
| 750 | /// This section reader provides an easy way to write an Lp problem |
---|
| 751 | /// to a file. The lemon lp section format contains three parts. |
---|
| 752 | /// |
---|
| 753 | ///\code |
---|
| 754 | /// @lp |
---|
| 755 | /// constraints |
---|
| 756 | /// 7 == x1 - 1 * x2 |
---|
| 757 | /// 2 * x1 + x3 / 2 <= 7 |
---|
| 758 | /// x2 + -3 * x3 >= 8 |
---|
| 759 | /// 3 <= x2 - 2 * x1 <= 8 |
---|
| 760 | /// bounds |
---|
| 761 | /// x1 >= 3 |
---|
| 762 | /// 2 <= x2 <= 5 |
---|
| 763 | /// 0 <= x3 <= 8 |
---|
| 764 | /// objective |
---|
| 765 | /// min x1 + 2 * x2 - x3 |
---|
| 766 | ///\endcode |
---|
| 767 | /// |
---|
| 768 | /// The first part gives the constraints to the lp. The constraints |
---|
| 769 | /// could be equality, lower bound, upper bound or range for an |
---|
| 770 | /// expression or equality, less or more for two expressions. |
---|
| 771 | /// |
---|
| 772 | /// The second part gives the bounds for the variables. The bounds |
---|
| 773 | /// could be the same as for the single expression so equality, |
---|
| 774 | /// lower bound, upper bound or range. |
---|
| 775 | /// |
---|
| 776 | /// The third part is the objective function, it should start with |
---|
| 777 | /// \c min or \c max and then a valid linear expression. |
---|
| 778 | /// |
---|
| 779 | /// If an LP variable does not have name in the writer, then it will |
---|
| 780 | /// automatically created in the writer. This make a slight change |
---|
| 781 | /// in the \c const variable. |
---|
| 782 | /// |
---|
| 783 | /// The basic way to write an LP problem is made by the next code: |
---|
| 784 | ///\code |
---|
| 785 | /// Lp lp; |
---|
| 786 | /// |
---|
| 787 | /// LemonWriter writer(filename_or_ostream); |
---|
| 788 | /// LpWriter lpwriter(writer, lp); |
---|
| 789 | /// |
---|
| 790 | /// writer.run(); |
---|
| 791 | ///\endcode |
---|
| 792 | /// |
---|
| 793 | /// Of course instead of \c LemonWriter you can give a \c |
---|
| 794 | /// GraphWriter to the LpWriter constructor. Also useful that you |
---|
| 795 | /// can mix lp problems and graphs in the same file. |
---|
[2364] | 796 | class LpWriter : public LemonWriter::SectionWriter { |
---|
| 797 | typedef LemonWriter::SectionWriter Parent; |
---|
| 798 | public: |
---|
[2363] | 799 | |
---|
| 800 | |
---|
[2364] | 801 | /// \brief Constructor. |
---|
| 802 | /// |
---|
| 803 | /// Constructor for LpWriter. It creates the LpWriter and attach |
---|
[2368] | 804 | /// it into the given LemonWriter. |
---|
| 805 | LpWriter(LemonWriter& _writer, const LpSolverBase& _lp, |
---|
[2364] | 806 | const std::string& _name = std::string()) |
---|
| 807 | : Parent(_writer), lp(_lp), name(_name) {} |
---|
[2363] | 808 | |
---|
| 809 | |
---|
[2364] | 810 | /// \brief Destructor. |
---|
| 811 | /// |
---|
[2368] | 812 | /// Destructor for LpWriter. |
---|
[2364] | 813 | virtual ~LpWriter() {} |
---|
[2363] | 814 | |
---|
[2364] | 815 | private: |
---|
| 816 | LpWriter(const LpWriter&); |
---|
| 817 | void operator=(const LpWriter&); |
---|
[2363] | 818 | |
---|
[2364] | 819 | protected: |
---|
[2363] | 820 | |
---|
[2364] | 821 | /// \brief Gives back true when the SectionWriter can process |
---|
| 822 | /// the section with the given header line. |
---|
| 823 | /// |
---|
| 824 | /// It gives back the header line of the \c \@lp section. |
---|
| 825 | virtual std::string header() { |
---|
| 826 | std::ostringstream ls; |
---|
| 827 | ls << "@lp " << name; |
---|
| 828 | return ls.str(); |
---|
| 829 | } |
---|
[2363] | 830 | |
---|
[2364] | 831 | private: |
---|
[2363] | 832 | |
---|
[2364] | 833 | void createCols() { |
---|
[2368] | 834 | int num = 0; |
---|
[2364] | 835 | |
---|
| 836 | for (LpSolverBase::ColIt it(lp); it != INVALID; ++it) { |
---|
| 837 | std::string name = lp.colName(it); |
---|
[2368] | 838 | if (name.empty()) { |
---|
[2364] | 839 | std::ostringstream ls; |
---|
[2368] | 840 | ls << "x" << num; |
---|
[2364] | 841 | ++num; |
---|
[2368] | 842 | while (lp.colByName(ls.str()) != INVALID) { |
---|
| 843 | ls.str(std::string()); |
---|
| 844 | ls << "x" << num; |
---|
| 845 | ++num; |
---|
| 846 | } |
---|
| 847 | const_cast<LpSolverBase&>(lp).colName(it, ls.str()); |
---|
[2364] | 848 | } |
---|
| 849 | } |
---|
| 850 | } |
---|
| 851 | |
---|
| 852 | void writeExpression(std::ostream& os, const LpSolverBase::Expr& e) { |
---|
| 853 | bool first = true; |
---|
| 854 | for (LpSolverBase::Expr::const_iterator jt = e.begin(); |
---|
| 855 | jt != e.end(); ++jt) { |
---|
| 856 | if (jt->second < 0.0) { |
---|
| 857 | os << "- "; |
---|
| 858 | if (jt->second != -1.0) { |
---|
| 859 | os << -jt->second << " * "; |
---|
| 860 | } |
---|
| 861 | } else if (jt->second > 0.0) { |
---|
| 862 | if (!first) { |
---|
| 863 | os << "+ "; |
---|
| 864 | } |
---|
| 865 | if (jt->second != 1.0) { |
---|
| 866 | os << jt->second << " * "; |
---|
| 867 | } |
---|
| 868 | } |
---|
| 869 | first = false; |
---|
[2368] | 870 | os << lp.colName(jt->first) << " "; |
---|
[2364] | 871 | } |
---|
| 872 | if (e.constComp() < 0.0) { |
---|
| 873 | os << "- " << -e.constComp() << " "; |
---|
| 874 | } else if (e.constComp() > 0.0) { |
---|
| 875 | if (!first) { |
---|
| 876 | os << "+ "; |
---|
| 877 | } |
---|
| 878 | os << e.constComp() << " "; |
---|
| 879 | } |
---|
| 880 | } |
---|
| 881 | |
---|
| 882 | protected: |
---|
| 883 | |
---|
| 884 | /// \brief Writer function of the section. |
---|
| 885 | /// |
---|
| 886 | /// It writes the content of the section. |
---|
| 887 | virtual void write(std::ostream& os) { |
---|
| 888 | createCols(); |
---|
| 889 | |
---|
| 890 | os << "constraints" << std::endl; |
---|
[2363] | 891 | |
---|
[2364] | 892 | for (LpSolverBase::RowIt it(lp); it != INVALID; ++it) { |
---|
| 893 | double lower, upper; |
---|
| 894 | lp.getRowBounds(it, lower, upper); |
---|
| 895 | if (lower == -LpSolverBase::INF && upper == LpSolverBase::INF) |
---|
| 896 | continue; |
---|
| 897 | os << " "; |
---|
| 898 | |
---|
| 899 | if (lower != upper) { |
---|
| 900 | if (lower != -LpSolverBase::INF) { |
---|
| 901 | os << lower << " <= "; |
---|
| 902 | } |
---|
| 903 | |
---|
| 904 | writeExpression(os, lp.row(it)); |
---|
| 905 | |
---|
| 906 | if (upper != LpSolverBase::INF) { |
---|
| 907 | os << "<= " << upper << " "; |
---|
| 908 | } |
---|
| 909 | } else { |
---|
[2363] | 910 | |
---|
[2364] | 911 | writeExpression(os, lp.row(it)); |
---|
| 912 | os << "== " << upper << " "; |
---|
| 913 | |
---|
| 914 | } |
---|
[2363] | 915 | |
---|
[2364] | 916 | os << std::endl; |
---|
| 917 | } |
---|
[2363] | 918 | |
---|
[2364] | 919 | os << "bounds" << std::endl; |
---|
| 920 | |
---|
| 921 | for (LpSolverBase::ColIt it(lp); it != INVALID; ++it) { |
---|
| 922 | double lower = lp.colLowerBound(it); |
---|
| 923 | double upper = lp.colUpperBound(it); |
---|
| 924 | if (lower == -LpSolverBase::INF && upper == LpSolverBase::INF) |
---|
| 925 | continue; |
---|
| 926 | os << " "; |
---|
[2363] | 927 | |
---|
[2364] | 928 | if (lower != upper) { |
---|
| 929 | if (lower != -LpSolverBase::INF) { |
---|
| 930 | os << lower << " <= "; |
---|
| 931 | } |
---|
| 932 | |
---|
[2368] | 933 | os << lp.colName(it) << " "; |
---|
[2364] | 934 | |
---|
| 935 | if (upper != LpSolverBase::INF) { |
---|
| 936 | os << "<= " << upper << " "; |
---|
| 937 | } |
---|
| 938 | } else { |
---|
[2368] | 939 | os << lp.colName(it) << " == " << upper << " "; |
---|
[2364] | 940 | } |
---|
| 941 | os << std::endl; |
---|
| 942 | } |
---|
[2363] | 943 | |
---|
[2364] | 944 | os << "objective" << std::endl; |
---|
| 945 | os << " "; |
---|
| 946 | if (lp.is_min()) { |
---|
| 947 | os << "min "; |
---|
| 948 | } else { |
---|
| 949 | os << "max "; |
---|
| 950 | } |
---|
| 951 | writeExpression(os, lp.obj()); |
---|
| 952 | os << std::endl; |
---|
| 953 | } |
---|
| 954 | |
---|
[2363] | 955 | |
---|
[2364] | 956 | private: |
---|
[2363] | 957 | |
---|
[2368] | 958 | const LpSolverBase& lp; |
---|
[2364] | 959 | std::string name; |
---|
| 960 | }; |
---|
[2363] | 961 | |
---|
[2316] | 962 | } |
---|
| 963 | |
---|
| 964 | #endif |
---|