[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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[2370] | 33 | /// \ingroup lp_utils |
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[2368] | 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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[2370] | 54 | /// \ingroup lp_utils |
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| 55 | /// |
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| 56 | /// \brief Returns an \ref LpResultMap class |
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| 57 | /// |
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| 58 | /// This function just returns an \ref LpResultMap class. |
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| 59 | /// \relates LpResultMap |
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| 60 | LpResultMap lpResultMap(const LpSolverBase& lp) { |
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| 61 | return LpResultMap(lp); |
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| 62 | } |
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| 63 | |
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| 64 | /// \ingroup lp_utils |
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[2368] | 65 | /// |
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| 66 | /// \brief The map for the name of the lp variables. |
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| 67 | /// |
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| 68 | /// The map for the name of the lp variables. |
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| 69 | class LpColNameMap { |
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| 70 | public: |
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| 71 | typedef LpSolverBase::Col Key; |
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| 72 | typedef std::string Value; |
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| 73 | |
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| 74 | /// \brief Constructor |
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| 75 | /// |
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| 76 | /// Constructor |
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| 77 | LpColNameMap(const LpSolverBase& _lp) : lp(_lp) {} |
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| 78 | std::string operator[](const LpSolverBase::Col col) const { |
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| 79 | return lp.colName(col); |
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| 80 | } |
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| 81 | private: |
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| 82 | const LpSolverBase& lp; |
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| 83 | }; |
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| 84 | |
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[2370] | 85 | /// \ingroup lp_utils |
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[2368] | 86 | /// |
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| 87 | /// \brief Writeable map for the name of the lp variables. |
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| 88 | /// |
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| 89 | /// Writeable map for the name of the lp variables. |
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| 90 | class LpColNameWriteMap { |
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| 91 | public: |
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| 92 | typedef LpSolverBase::Col Key; |
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| 93 | typedef std::string Value; |
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| 94 | |
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| 95 | /// \brief Constructor |
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| 96 | /// |
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| 97 | /// Constructor |
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| 98 | LpColNameWriteMap(LpSolverBase& _lp) : lp(_lp) {} |
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| 99 | std::string operator[](const LpSolverBase::Col col) const { |
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| 100 | return lp.colName(col); |
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| 101 | } |
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| 102 | void set(const LpSolverBase::Col col, const std::string& name) { |
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| 103 | lp.colName(col, name); |
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| 104 | } |
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| 105 | private: |
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| 106 | LpSolverBase& lp; |
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| 107 | }; |
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| 108 | |
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[2370] | 109 | /// \ingroup lp_utils |
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[2368] | 110 | /// |
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| 111 | /// \brief Returns an \ref LpColNameMap class |
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| 112 | /// |
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| 113 | /// This function just returns an \ref LpColNameMap class. |
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| 114 | /// \relates LpColNameMap |
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| 115 | LpColNameMap lpColNameMap(const LpSolverBase& lp) { |
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| 116 | return LpColNameMap(lp); |
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| 117 | } |
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| 118 | |
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| 119 | LpColNameWriteMap lpColNameMap(LpSolverBase& lp) { |
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| 120 | return LpColNameWriteMap(lp); |
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| 121 | } |
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| 122 | |
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[2370] | 123 | /// \ingroup lp_utils |
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[2368] | 124 | /// |
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| 125 | /// \brief Lp variable item reader for Lemon IO |
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| 126 | /// |
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| 127 | /// This class is an Lp variable item reader for Lemon IO. It makes |
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| 128 | /// possible to store lp variables in lemon file. The usage of this |
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| 129 | /// class is very simple: |
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| 130 | /// |
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| 131 | ///\code |
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| 132 | /// Graph graph; |
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| 133 | /// Lp lp; |
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| 134 | /// Graph::EdgeMap<Lp::Col> var(graph); |
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| 135 | /// |
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| 136 | /// GraphReader<Graph> reader(cin, graph); |
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| 137 | /// reader.readEdgeMap("lpvar", var, LpColReader(lp)); |
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| 138 | /// reader.run(); |
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| 139 | ///\endcode |
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| 140 | /// |
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| 141 | /// If there is already a variable with the same name in the lp then |
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| 142 | /// it will be used for the return value. If there is no such variable |
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| 143 | /// then it will be constructed. The file could contain \c '-' as value |
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| 144 | /// which means that no lp variable associated to the current item and |
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| 145 | /// in this case INVALID will be returned. |
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| 146 | class LpColReader { |
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| 147 | public: |
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| 148 | |
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| 149 | /// \brief The value type of reader. |
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| 150 | /// |
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| 151 | /// The value type of reader. |
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| 152 | typedef LpSolverBase::Col Value; |
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| 153 | |
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| 154 | /// \brief Constructor for the reader. |
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| 155 | /// |
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| 156 | /// Constructor for the reader. |
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| 157 | LpColReader(LpSolverBase& _lp) : lp(_lp) {} |
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| 158 | |
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| 159 | /// \brief Reads an lp variable from the given stream. |
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| 160 | /// |
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| 161 | /// Reads an lp variable string from the given stream. |
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| 162 | void read(std::istream& is, LpSolverBase::Col& col) const { |
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| 163 | char x; |
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| 164 | is >> std::ws; |
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| 165 | if (!is.get(x)) |
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| 166 | throw DataFormatError("Wrong Lp Column format!"); |
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| 167 | if (varFirstChar(x)) { |
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| 168 | std::string var; |
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| 169 | var += x; |
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| 170 | |
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| 171 | while (is.get(x) && varChar(x)) { |
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| 172 | var += x; |
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| 173 | } |
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| 174 | if (!is) { |
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| 175 | is.clear(); |
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| 176 | } else { |
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| 177 | is.putback(x); |
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| 178 | } |
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| 179 | col = lp.colByName(var); |
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| 180 | if (col == INVALID) { |
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| 181 | col = lp.addCol(); |
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| 182 | lp.colName(col, var); |
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| 183 | } |
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| 184 | } else if (x == '-') { |
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| 185 | col = INVALID; |
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| 186 | is >> std::ws; |
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| 187 | } else { |
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| 188 | std::cerr << x << std::endl; |
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| 189 | throw DataFormatError("Wrong Lp Column format"); |
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| 190 | } |
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| 191 | } |
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| 192 | |
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| 193 | private: |
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| 194 | |
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| 195 | static bool varFirstChar(char c) { |
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| 196 | return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z'); |
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| 197 | } |
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| 198 | |
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| 199 | static bool varChar(char c) { |
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| 200 | return (c >= '0' && c <= '9') || |
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| 201 | (c >= 'a' && c <= 'z') || |
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| 202 | (c >= 'A' && c <= 'Z') || |
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| 203 | c == '[' || c == ']'; |
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| 204 | } |
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| 205 | |
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| 206 | LpSolverBase& lp; |
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| 207 | |
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| 208 | }; |
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| 209 | |
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[2370] | 210 | /// \ingroup lp_utils |
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[2368] | 211 | /// |
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| 212 | /// \brief Lp variable item writer for Lemon IO |
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| 213 | /// |
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| 214 | /// This class is an Lp variable item writer for Lemon IO. It makes |
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| 215 | /// possible to store lp variables in lemon file. The usage of this |
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| 216 | /// class is very simple: |
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| 217 | /// |
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| 218 | ///\code |
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| 219 | /// Graph graph; |
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| 220 | /// Lp lp; |
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| 221 | /// Graph::EdgeMap<Lp::Col> var(graph); |
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| 222 | /// |
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| 223 | /// GraphWriter<Graph> writer(cin, graph); |
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| 224 | /// writer.writeEdgeMap("lpvar", var, LpColWriter(lp)); |
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| 225 | /// writer.run(); |
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| 226 | ///\endcode |
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| 227 | /// |
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| 228 | /// If there is no name associated to the current item then the name |
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| 229 | /// will automatically constructed. If the value is INVALID then it |
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| 230 | /// will write an \c '-' value to the file. |
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| 231 | class LpColWriter { |
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| 232 | public: |
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| 233 | |
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| 234 | /// \brief The value type of writer. |
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| 235 | /// |
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| 236 | /// The value type of writer. |
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| 237 | typedef LpSolverBase::Col Value; |
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| 238 | |
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| 239 | /// \brief Constructor for the writer. |
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| 240 | /// |
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| 241 | /// Constructor for the writer. |
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| 242 | LpColWriter(const LpSolverBase& _lp) : lp(_lp), num(0) {} |
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| 243 | |
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| 244 | /// \brief Writes an lp variable to the given stream. |
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| 245 | /// |
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| 246 | /// Writes an lp variable to the given stream. |
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| 247 | void write(std::ostream& os, const LpSolverBase::Col& col) const { |
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| 248 | if (col != INVALID) { |
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| 249 | std::string name = lp.colName(col); |
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| 250 | if (name.empty()) { |
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| 251 | std::ostringstream ls; |
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| 252 | ls << "x" << num; |
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| 253 | ++num; |
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| 254 | while (lp.colByName(ls.str()) != INVALID) { |
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| 255 | ls.str(std::string()); |
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| 256 | ls << "x" << num; |
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| 257 | ++num; |
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| 258 | } |
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| 259 | const_cast<LpSolverBase&>(lp).colName(col, ls.str()); |
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| 260 | os << ls.str(); |
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| 261 | } else { |
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| 262 | os << name; |
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| 263 | } |
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| 264 | } else { |
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| 265 | os << "-"; |
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| 266 | } |
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| 267 | } |
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| 268 | |
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| 269 | private: |
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| 270 | |
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| 271 | const LpSolverBase& lp; |
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| 272 | mutable int num; |
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| 273 | |
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| 274 | }; |
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| 275 | |
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[2370] | 276 | /// \ingroup lp_utils |
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[2368] | 277 | /// |
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| 278 | /// \brief Lp section reader for lemon IO |
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| 279 | /// |
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| 280 | /// This section reader provides an easy way to read an Lp problem |
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| 281 | /// from a file. The lemon lp section format contains three parts. |
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| 282 | /// |
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| 283 | ///\code |
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| 284 | /// @lp |
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| 285 | /// constraints |
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| 286 | /// 7 == x1 - 1 * x2 |
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| 287 | /// 2 * x1 + x3 / 2 <= 7 |
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| 288 | /// x2 + -3 * x3 >= 8 |
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| 289 | /// 3 <= x2 - 2 * x1 <= 8 |
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| 290 | /// bounds |
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| 291 | /// x1 >= 3 |
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| 292 | /// 2 <= x2 <= 5 |
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| 293 | /// 0 <= x3 <= 8 |
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| 294 | /// objective |
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| 295 | /// min x1 + 2 * x2 - x3 |
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| 296 | ///\endcode |
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| 297 | /// |
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| 298 | /// The first part gives the constraints to the lp. The constraints |
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| 299 | /// could be equality, lower bound, upper bound or range for an |
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| 300 | /// expression or equality, less or more for two expressions. |
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| 301 | /// |
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| 302 | /// The second part gives the bounds for the variables. The bounds |
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| 303 | /// could be the same as for the single expression so equality, |
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| 304 | /// lower bound, upper bound or range. |
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| 305 | /// |
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| 306 | /// The third part is the objective function, it should start with |
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| 307 | /// \c min or \c max and then a valid linear expression. |
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| 308 | /// |
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| 309 | /// The reader constructs automatically the variable for a name if |
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| 310 | /// there is not already a variable with the same name. |
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| 311 | /// |
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| 312 | /// The basic way to read an LP problem is made by the next code: |
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| 313 | ///\code |
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| 314 | /// Lp lp; |
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| 315 | /// |
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| 316 | /// LemonReader reader(filename_or_istream); |
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| 317 | /// LpReader lpreader(reader, lp); |
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| 318 | /// |
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| 319 | /// reader.run(); |
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| 320 | ///\endcode |
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| 321 | /// |
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| 322 | /// Of course instead of \c LemonReader you can give a \c |
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| 323 | /// GraphReader to the LpReader constructor. Also useful that you |
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| 324 | /// can mix lp problems and graphs in the same file. |
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[2316] | 325 | class LpReader : public LemonReader::SectionReader { |
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| 326 | typedef LemonReader::SectionReader Parent; |
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| 327 | public: |
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| 328 | |
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| 329 | |
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| 330 | /// \brief Constructor. |
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| 331 | /// |
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[2368] | 332 | /// Constructor for LpReader. It creates the LpReader and attachs |
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[2316] | 333 | /// it into the given LemonReader. The lp reader will add |
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| 334 | /// variables, constraints and objective function to the |
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| 335 | /// given lp solver. |
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| 336 | LpReader(LemonReader& _reader, LpSolverBase& _lp, |
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| 337 | const std::string& _name = std::string()) |
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| 338 | : Parent(_reader), lp(_lp), name(_name) {} |
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| 339 | |
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| 340 | |
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| 341 | /// \brief Destructor. |
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| 342 | /// |
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[2368] | 343 | /// Destructor for LpReader. |
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[2316] | 344 | virtual ~LpReader() {} |
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| 345 | |
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| 346 | private: |
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| 347 | LpReader(const LpReader&); |
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| 348 | void operator=(const LpReader&); |
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| 349 | |
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| 350 | protected: |
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| 351 | |
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| 352 | /// \brief Gives back true when the SectionReader can process |
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| 353 | /// the section with the given header line. |
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| 354 | /// |
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| 355 | /// It gives back true when the header line starts with \c \@lp, |
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| 356 | /// and the header line's name and the nodeset's name are the same. |
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| 357 | virtual bool header(const std::string& line) { |
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| 358 | std::istringstream ls(line); |
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| 359 | std::string command; |
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| 360 | std::string id; |
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| 361 | ls >> command >> id; |
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| 362 | return command == "@lp" && name == id; |
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| 363 | } |
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| 364 | |
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| 365 | private: |
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| 366 | |
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[2368] | 367 | enum Part { |
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[2364] | 368 | CONSTRAINTS, BOUNDS, OBJECTIVE |
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| 369 | }; |
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| 370 | |
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[2316] | 371 | enum Relation { |
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| 372 | LE, EQ, GE |
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| 373 | }; |
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| 374 | |
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[2364] | 375 | std::istream& readConstraint(std::istream& is) { |
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| 376 | LpSolverBase::Constr c; |
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[2316] | 377 | char x; |
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| 378 | LpSolverBase::Expr e1, e2; |
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| 379 | Relation op1; |
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| 380 | is >> std::ws; |
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| 381 | readExpression(is, e1); |
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| 382 | is >> std::ws; |
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| 383 | readRelation(is, op1); |
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| 384 | is >> std::ws; |
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| 385 | readExpression(is, e2); |
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[2364] | 386 | is >> std::ws; |
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[2316] | 387 | if (!is.get(x)) { |
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| 388 | if (op1 == LE) { |
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[2364] | 389 | if (e1.size() == 0) { |
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| 390 | c = e2 >= e1; |
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| 391 | } else { |
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| 392 | c = e1 <= e2; |
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| 393 | } |
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[2316] | 394 | c = e1 <= e2; |
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| 395 | } else if (op1 == GE) { |
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[2364] | 396 | if (e1.size() == 0) { |
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| 397 | c = e2 <= e1; |
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| 398 | } else { |
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| 399 | c = e1 >= e2; |
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| 400 | } |
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[2316] | 401 | } else { |
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[2364] | 402 | if (e1.size() == 0) { |
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| 403 | c = e2 == e1; |
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| 404 | } else { |
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| 405 | c = e1 == e2; |
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| 406 | } |
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[2316] | 407 | } |
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| 408 | } else { |
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| 409 | is.putback(x); |
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| 410 | LpSolverBase::Expr e3; |
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| 411 | Relation op2; |
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| 412 | readRelation(is, op2); |
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| 413 | is >> std::ws; |
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| 414 | readExpression(is, e3); |
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| 415 | if (!e1.empty() || !e3.empty()) { |
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| 416 | throw DataFormatError("Wrong range format"); |
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| 417 | } |
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| 418 | if (op2 != op1 || op1 == EQ) { |
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| 419 | throw DataFormatError("Wrong range format"); |
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| 420 | } |
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| 421 | if (op1 == LE) { |
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| 422 | c = e1.constComp() <= e2 <= e3.constComp(); |
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| 423 | } else { |
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| 424 | c = e1.constComp() >= e2 >= e3.constComp(); |
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| 425 | } |
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[2364] | 426 | is >> std::ws; |
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| 427 | if (is.get(x)) { |
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| 428 | throw DataFormatError("Wrong variable bounds format"); |
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| 429 | } |
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[2316] | 430 | } |
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[2364] | 431 | lp.addRow(c); |
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| 432 | return is; |
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| 433 | } |
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| 434 | |
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| 435 | std::istream& readObjective(std::istream& is) { |
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| 436 | is >> std::ws; |
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| 437 | std::string sense; |
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| 438 | is >> sense; |
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| 439 | if (sense != "min" && sense != "max") { |
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| 440 | throw DataFormatError("Wrong objective function format"); |
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| 441 | } |
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| 442 | LpSolverBase::Expr expr; |
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| 443 | is >> std::ws; |
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| 444 | readExpression(is, expr); |
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[2369] | 445 | lp.obj(expr); |
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[2364] | 446 | if (sense == "min") { |
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| 447 | lp.min(); |
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| 448 | } else { |
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| 449 | lp.max(); |
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| 450 | } |
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| 451 | return is; |
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| 452 | } |
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| 453 | |
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| 454 | std::istream& readBounds(std::istream& is) { |
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| 455 | LpSolverBase::Col c; |
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| 456 | char x; |
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| 457 | is >> std::ws; |
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| 458 | if (!is.get(x)) { |
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| 459 | throw DataFormatError("Wrong variable bounds format"); |
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| 460 | } |
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| 461 | if (varFirstChar(x)) { |
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| 462 | is.putback(x); |
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| 463 | readCol(is, c); |
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| 464 | is >> std::ws; |
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| 465 | Relation op1; |
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| 466 | readRelation(is, op1); |
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| 467 | double v; |
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| 468 | readNum(is, v); |
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| 469 | if (op1 == EQ) { |
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| 470 | lp.colLowerBound(c, v); |
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| 471 | lp.colUpperBound(c, v); |
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| 472 | } else if (op1 == LE) { |
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| 473 | lp.colUpperBound(c, v); |
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| 474 | } else { |
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| 475 | lp.colLowerBound(c, v); |
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| 476 | } |
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| 477 | is >> std::ws; |
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| 478 | if (is.get(x)) { |
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| 479 | throw DataFormatError("Wrong variable bounds format"); |
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| 480 | } |
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| 481 | } else { |
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| 482 | is.putback(x); |
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| 483 | double v; |
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| 484 | readNum(is, v); |
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| 485 | is >> std::ws; |
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| 486 | Relation op1; |
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| 487 | readRelation(is, op1); |
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| 488 | is >> std::ws; |
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| 489 | readCol(is, c); |
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| 490 | is >> std::ws; |
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| 491 | if (is.get(x)) { |
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| 492 | is.putback(x); |
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| 493 | is >> std::ws; |
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| 494 | Relation op2; |
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| 495 | readRelation(is, op2); |
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| 496 | double w; |
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| 497 | is >> std::ws; |
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| 498 | readNum(is, w); |
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| 499 | if (op2 != op1 || op1 == EQ) { |
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| 500 | throw DataFormatError("Wrong range format"); |
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| 501 | } |
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| 502 | if (op1 == LE) { |
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| 503 | lp.colLowerBound(c, v); |
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| 504 | lp.colUpperBound(c, w); |
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| 505 | } else { |
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| 506 | lp.colLowerBound(c, w); |
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| 507 | lp.colUpperBound(c, v); |
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| 508 | } |
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[2368] | 509 | is >> std::ws; |
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[2364] | 510 | if (is.get(x)) { |
---|
| 511 | throw DataFormatError("Wrong variable bounds format"); |
---|
| 512 | } |
---|
| 513 | } else { |
---|
| 514 | if (op1 == EQ) { |
---|
| 515 | lp.colLowerBound(c, v); |
---|
| 516 | lp.colUpperBound(c, v); |
---|
| 517 | } else if (op1 == LE) { |
---|
| 518 | lp.colLowerBound(c, v); |
---|
| 519 | } else { |
---|
| 520 | lp.colUpperBound(c, v); |
---|
| 521 | } |
---|
| 522 | } |
---|
| 523 | } |
---|
| 524 | return is; |
---|
[2316] | 525 | } |
---|
| 526 | |
---|
| 527 | std::istream& readExpression(std::istream& is, LpSolverBase::Expr& e) { |
---|
| 528 | LpSolverBase::Col c; |
---|
| 529 | double d; |
---|
| 530 | char x; |
---|
| 531 | readElement(is, c, d); |
---|
| 532 | if (c != INVALID) { |
---|
| 533 | e += d * c; |
---|
| 534 | } else { |
---|
| 535 | e += d; |
---|
| 536 | } |
---|
| 537 | is >> std::ws; |
---|
| 538 | while (is.get(x) && (x == '+' || x == '-')) { |
---|
| 539 | is >> std::ws; |
---|
| 540 | readElement(is, c, d); |
---|
| 541 | if (c != INVALID) { |
---|
| 542 | e += (x == '+' ? d : -d) * c; |
---|
| 543 | } else { |
---|
| 544 | e += (x == '+' ? d : -d); |
---|
| 545 | } |
---|
| 546 | is >> std::ws; |
---|
| 547 | } |
---|
| 548 | if (!is) { |
---|
| 549 | is.clear(); |
---|
| 550 | } else { |
---|
| 551 | is.putback(x); |
---|
| 552 | } |
---|
| 553 | return is; |
---|
| 554 | } |
---|
| 555 | |
---|
| 556 | std::istream& readElement(std::istream& is, |
---|
| 557 | LpSolverBase::Col& c, double& d) { |
---|
| 558 | d = 1.0; |
---|
| 559 | c = INVALID; |
---|
| 560 | char x, y; |
---|
| 561 | if (!is.get(x)) throw DataFormatError("Cannot find lp element"); |
---|
| 562 | if (x == '+' || x == '-') { |
---|
| 563 | is >> std::ws; |
---|
| 564 | d *= x == '-' ? -1 : 1; |
---|
| 565 | while (is.get(x) && (x == '+' || x == '-')) { |
---|
| 566 | d *= x == '-' ? -1 : 1; |
---|
| 567 | is >> std::ws; |
---|
| 568 | } |
---|
| 569 | if (!is) throw DataFormatError("Cannot find lp element"); |
---|
| 570 | } |
---|
| 571 | if (numFirstChar(x)) { |
---|
| 572 | is.putback(x); |
---|
| 573 | double e; |
---|
| 574 | readNum(is, e); |
---|
| 575 | d *= e; |
---|
| 576 | } else if (varFirstChar(x)) { |
---|
| 577 | is.putback(x); |
---|
| 578 | LpSolverBase::Col f; |
---|
| 579 | readCol(is, f); |
---|
| 580 | c = f; |
---|
| 581 | } else { |
---|
| 582 | throw DataFormatError("Invalid expression format"); |
---|
| 583 | } |
---|
| 584 | is >> std::ws; |
---|
| 585 | while (is.get(y) && (y == '*' || y == '/')) { |
---|
| 586 | is >> std::ws; |
---|
| 587 | if (!is.get(x)) throw DataFormatError("Cannot find lp element"); |
---|
| 588 | if (x == '+' || x == '-') { |
---|
| 589 | is >> std::ws; |
---|
| 590 | d *= x == '-' ? -1 : 1; |
---|
| 591 | while (is.get(x) && (x == '+' || x == '-')) { |
---|
| 592 | d *= x == '-' ? -1 : 1; |
---|
| 593 | is >> std::ws; |
---|
| 594 | } |
---|
| 595 | if (!is) throw DataFormatError("Cannot find lp element"); |
---|
| 596 | } |
---|
| 597 | if (numFirstChar(x)) { |
---|
| 598 | is.putback(x); |
---|
| 599 | double e; |
---|
| 600 | readNum(is, e); |
---|
| 601 | if (y == '*') { |
---|
| 602 | d *= e; |
---|
| 603 | } else { |
---|
| 604 | d /= e; |
---|
| 605 | } |
---|
| 606 | } else if (varFirstChar(x)) { |
---|
| 607 | is.putback(x); |
---|
| 608 | LpSolverBase::Col f; |
---|
| 609 | readCol(is, f); |
---|
| 610 | if (y == '*') { |
---|
| 611 | if (c == INVALID) { |
---|
| 612 | c = f; |
---|
| 613 | } else { |
---|
| 614 | throw DataFormatError("Quadratic element in expression"); |
---|
| 615 | } |
---|
| 616 | } else { |
---|
| 617 | throw DataFormatError("Division by variable"); |
---|
| 618 | } |
---|
| 619 | } else { |
---|
| 620 | throw DataFormatError("Invalid expression format"); |
---|
| 621 | } |
---|
| 622 | is >> std::ws; |
---|
| 623 | } |
---|
| 624 | if (!is) { |
---|
| 625 | is.clear(); |
---|
| 626 | } else { |
---|
| 627 | is.putback(y); |
---|
| 628 | } |
---|
| 629 | return is; |
---|
| 630 | } |
---|
| 631 | |
---|
| 632 | std::istream& readCol(std::istream& is, LpSolverBase::Col& c) { |
---|
| 633 | char x; |
---|
| 634 | std::string var; |
---|
| 635 | while (is.get(x) && varChar(x)) { |
---|
| 636 | var += x; |
---|
| 637 | } |
---|
| 638 | if (!is) { |
---|
| 639 | is.clear(); |
---|
| 640 | } else { |
---|
| 641 | is.putback(x); |
---|
| 642 | } |
---|
[2368] | 643 | c = lp.colByName(var); |
---|
| 644 | if (c == INVALID) { |
---|
[2316] | 645 | c = lp.addCol(); |
---|
| 646 | lp.colName(c, var); |
---|
| 647 | } |
---|
| 648 | return is; |
---|
| 649 | } |
---|
| 650 | |
---|
| 651 | std::istream& readNum(std::istream& is, double& d) { |
---|
| 652 | is >> d; |
---|
| 653 | if (!is) throw DataFormatError("Wrong number format"); |
---|
| 654 | return is; |
---|
| 655 | } |
---|
| 656 | |
---|
| 657 | std::istream& readRelation(std::istream& is, Relation& op) { |
---|
| 658 | char x, y; |
---|
| 659 | if (!is.get(x) || !(x == '<' || x == '=' || x == '>')) { |
---|
| 660 | throw DataFormatError("Wrong relation operator"); |
---|
| 661 | } |
---|
| 662 | if (!is.get(y) || y != '=') { |
---|
| 663 | throw DataFormatError("Wrong relation operator"); |
---|
| 664 | } |
---|
| 665 | switch (x) { |
---|
| 666 | case '<': op = LE; |
---|
| 667 | break; |
---|
| 668 | case '=': op = EQ; |
---|
| 669 | break; |
---|
| 670 | case '>': op = GE; |
---|
| 671 | break; |
---|
| 672 | } |
---|
| 673 | return is; |
---|
| 674 | } |
---|
| 675 | |
---|
| 676 | static bool relationFirstChar(char c) { |
---|
| 677 | return c == '<' || c == '=' || c == '>'; |
---|
| 678 | } |
---|
| 679 | |
---|
| 680 | static bool varFirstChar(char c) { |
---|
| 681 | return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z'); |
---|
| 682 | } |
---|
| 683 | |
---|
| 684 | static bool numFirstChar(char c) { |
---|
| 685 | return (c >= '0' && c <= '9') || c == '.'; |
---|
| 686 | } |
---|
[2368] | 687 | |
---|
[2316] | 688 | static bool varChar(char c) { |
---|
| 689 | return (c >= '0' && c <= '9') || |
---|
[2364] | 690 | (c >= 'a' && c <= 'z') || |
---|
| 691 | (c >= 'A' && c <= 'Z') || |
---|
| 692 | c == '[' || c == ']'; |
---|
[2316] | 693 | } |
---|
| 694 | |
---|
| 695 | protected: |
---|
| 696 | |
---|
| 697 | /// \brief Reader function of the section. |
---|
| 698 | /// |
---|
| 699 | /// It reads the content of the section. |
---|
| 700 | virtual void read(std::istream& is) { |
---|
| 701 | std::string line; |
---|
[2368] | 702 | Part part = CONSTRAINTS; |
---|
[2316] | 703 | while (getline(is, line)) { |
---|
| 704 | std::istringstream ls(line); |
---|
[2364] | 705 | std::string type; |
---|
| 706 | ls >> type; |
---|
| 707 | if (type == "constraints") { |
---|
[2368] | 708 | part = CONSTRAINTS; |
---|
| 709 | ls >> std::ws; |
---|
| 710 | char x; |
---|
| 711 | if (ls.get(x)) |
---|
| 712 | throw DataFormatError("Wrong Lp format"); |
---|
[2364] | 713 | } else if (type == "bounds") { |
---|
[2368] | 714 | part = BOUNDS; |
---|
| 715 | ls >> std::ws; |
---|
| 716 | char x; |
---|
| 717 | if (ls.get(x)) |
---|
| 718 | throw DataFormatError("Wrong Lp format"); |
---|
[2364] | 719 | } else if (type == "objective") { |
---|
[2368] | 720 | part = OBJECTIVE; |
---|
| 721 | ls >> std::ws; |
---|
| 722 | char x; |
---|
| 723 | if (ls.get(x)) |
---|
| 724 | throw DataFormatError("Wrong Lp format"); |
---|
[2316] | 725 | } else { |
---|
| 726 | ls.str(line); |
---|
[2368] | 727 | switch (part) { |
---|
[2364] | 728 | case CONSTRAINTS: |
---|
| 729 | readConstraint(ls); |
---|
| 730 | break; |
---|
| 731 | case BOUNDS: |
---|
| 732 | readBounds(ls); |
---|
| 733 | break; |
---|
| 734 | case OBJECTIVE: |
---|
| 735 | readObjective(ls); |
---|
| 736 | break; |
---|
| 737 | } |
---|
[2368] | 738 | } |
---|
[2316] | 739 | } |
---|
| 740 | } |
---|
| 741 | |
---|
| 742 | virtual void missing() { |
---|
| 743 | ErrorMessage msg; |
---|
| 744 | msg << "Lp section not found in file: @lp " << name; |
---|
| 745 | throw IoParameterError(msg.message()); |
---|
| 746 | } |
---|
| 747 | |
---|
| 748 | private: |
---|
| 749 | |
---|
| 750 | |
---|
| 751 | LpSolverBase& lp; |
---|
| 752 | std::string name; |
---|
| 753 | }; |
---|
| 754 | |
---|
[2363] | 755 | |
---|
[2370] | 756 | /// \ingroup lp_utils |
---|
[2368] | 757 | /// |
---|
| 758 | /// \brief Lp section writer for lemon IO |
---|
| 759 | /// |
---|
| 760 | /// This section reader provides an easy way to write an Lp problem |
---|
| 761 | /// to a file. The lemon lp section format contains three parts. |
---|
| 762 | /// |
---|
| 763 | ///\code |
---|
| 764 | /// @lp |
---|
| 765 | /// constraints |
---|
| 766 | /// 7 == x1 - 1 * x2 |
---|
| 767 | /// 2 * x1 + x3 / 2 <= 7 |
---|
| 768 | /// x2 + -3 * x3 >= 8 |
---|
| 769 | /// 3 <= x2 - 2 * x1 <= 8 |
---|
| 770 | /// bounds |
---|
| 771 | /// x1 >= 3 |
---|
| 772 | /// 2 <= x2 <= 5 |
---|
| 773 | /// 0 <= x3 <= 8 |
---|
| 774 | /// objective |
---|
| 775 | /// min x1 + 2 * x2 - x3 |
---|
| 776 | ///\endcode |
---|
| 777 | /// |
---|
| 778 | /// The first part gives the constraints to the lp. The constraints |
---|
| 779 | /// could be equality, lower bound, upper bound or range for an |
---|
| 780 | /// expression or equality, less or more for two expressions. |
---|
| 781 | /// |
---|
| 782 | /// The second part gives the bounds for the variables. The bounds |
---|
| 783 | /// could be the same as for the single expression so equality, |
---|
| 784 | /// lower bound, upper bound or range. |
---|
| 785 | /// |
---|
| 786 | /// The third part is the objective function, it should start with |
---|
| 787 | /// \c min or \c max and then a valid linear expression. |
---|
| 788 | /// |
---|
| 789 | /// If an LP variable does not have name in the writer, then it will |
---|
| 790 | /// automatically created in the writer. This make a slight change |
---|
| 791 | /// in the \c const variable. |
---|
| 792 | /// |
---|
| 793 | /// The basic way to write an LP problem is made by the next code: |
---|
| 794 | ///\code |
---|
| 795 | /// Lp lp; |
---|
| 796 | /// |
---|
| 797 | /// LemonWriter writer(filename_or_ostream); |
---|
| 798 | /// LpWriter lpwriter(writer, lp); |
---|
| 799 | /// |
---|
| 800 | /// writer.run(); |
---|
| 801 | ///\endcode |
---|
| 802 | /// |
---|
| 803 | /// Of course instead of \c LemonWriter you can give a \c |
---|
| 804 | /// GraphWriter to the LpWriter constructor. Also useful that you |
---|
| 805 | /// can mix lp problems and graphs in the same file. |
---|
[2364] | 806 | class LpWriter : public LemonWriter::SectionWriter { |
---|
| 807 | typedef LemonWriter::SectionWriter Parent; |
---|
| 808 | public: |
---|
[2363] | 809 | |
---|
| 810 | |
---|
[2364] | 811 | /// \brief Constructor. |
---|
| 812 | /// |
---|
| 813 | /// Constructor for LpWriter. It creates the LpWriter and attach |
---|
[2368] | 814 | /// it into the given LemonWriter. |
---|
| 815 | LpWriter(LemonWriter& _writer, const LpSolverBase& _lp, |
---|
[2364] | 816 | const std::string& _name = std::string()) |
---|
| 817 | : Parent(_writer), lp(_lp), name(_name) {} |
---|
[2363] | 818 | |
---|
| 819 | |
---|
[2364] | 820 | /// \brief Destructor. |
---|
| 821 | /// |
---|
[2368] | 822 | /// Destructor for LpWriter. |
---|
[2364] | 823 | virtual ~LpWriter() {} |
---|
[2363] | 824 | |
---|
[2364] | 825 | private: |
---|
| 826 | LpWriter(const LpWriter&); |
---|
| 827 | void operator=(const LpWriter&); |
---|
[2363] | 828 | |
---|
[2364] | 829 | protected: |
---|
[2363] | 830 | |
---|
[2364] | 831 | /// \brief Gives back true when the SectionWriter can process |
---|
| 832 | /// the section with the given header line. |
---|
| 833 | /// |
---|
| 834 | /// It gives back the header line of the \c \@lp section. |
---|
| 835 | virtual std::string header() { |
---|
| 836 | std::ostringstream ls; |
---|
| 837 | ls << "@lp " << name; |
---|
| 838 | return ls.str(); |
---|
| 839 | } |
---|
[2363] | 840 | |
---|
[2364] | 841 | private: |
---|
[2363] | 842 | |
---|
[2364] | 843 | void createCols() { |
---|
[2368] | 844 | int num = 0; |
---|
[2364] | 845 | |
---|
| 846 | for (LpSolverBase::ColIt it(lp); it != INVALID; ++it) { |
---|
| 847 | std::string name = lp.colName(it); |
---|
[2368] | 848 | if (name.empty()) { |
---|
[2364] | 849 | std::ostringstream ls; |
---|
[2368] | 850 | ls << "x" << num; |
---|
[2364] | 851 | ++num; |
---|
[2368] | 852 | while (lp.colByName(ls.str()) != INVALID) { |
---|
| 853 | ls.str(std::string()); |
---|
| 854 | ls << "x" << num; |
---|
| 855 | ++num; |
---|
| 856 | } |
---|
| 857 | const_cast<LpSolverBase&>(lp).colName(it, ls.str()); |
---|
[2364] | 858 | } |
---|
| 859 | } |
---|
| 860 | } |
---|
| 861 | |
---|
| 862 | void writeExpression(std::ostream& os, const LpSolverBase::Expr& e) { |
---|
| 863 | bool first = true; |
---|
| 864 | for (LpSolverBase::Expr::const_iterator jt = e.begin(); |
---|
| 865 | jt != e.end(); ++jt) { |
---|
| 866 | if (jt->second < 0.0) { |
---|
| 867 | os << "- "; |
---|
| 868 | if (jt->second != -1.0) { |
---|
| 869 | os << -jt->second << " * "; |
---|
| 870 | } |
---|
| 871 | } else if (jt->second > 0.0) { |
---|
| 872 | if (!first) { |
---|
| 873 | os << "+ "; |
---|
| 874 | } |
---|
| 875 | if (jt->second != 1.0) { |
---|
| 876 | os << jt->second << " * "; |
---|
| 877 | } |
---|
| 878 | } |
---|
| 879 | first = false; |
---|
[2368] | 880 | os << lp.colName(jt->first) << " "; |
---|
[2364] | 881 | } |
---|
| 882 | if (e.constComp() < 0.0) { |
---|
| 883 | os << "- " << -e.constComp() << " "; |
---|
| 884 | } else if (e.constComp() > 0.0) { |
---|
| 885 | if (!first) { |
---|
| 886 | os << "+ "; |
---|
| 887 | } |
---|
| 888 | os << e.constComp() << " "; |
---|
| 889 | } |
---|
| 890 | } |
---|
| 891 | |
---|
| 892 | protected: |
---|
| 893 | |
---|
| 894 | /// \brief Writer function of the section. |
---|
| 895 | /// |
---|
| 896 | /// It writes the content of the section. |
---|
| 897 | virtual void write(std::ostream& os) { |
---|
| 898 | createCols(); |
---|
| 899 | |
---|
| 900 | os << "constraints" << std::endl; |
---|
[2363] | 901 | |
---|
[2364] | 902 | for (LpSolverBase::RowIt it(lp); it != INVALID; ++it) { |
---|
| 903 | double lower, upper; |
---|
| 904 | lp.getRowBounds(it, lower, upper); |
---|
| 905 | if (lower == -LpSolverBase::INF && upper == LpSolverBase::INF) |
---|
| 906 | continue; |
---|
| 907 | os << " "; |
---|
| 908 | |
---|
| 909 | if (lower != upper) { |
---|
| 910 | if (lower != -LpSolverBase::INF) { |
---|
| 911 | os << lower << " <= "; |
---|
| 912 | } |
---|
| 913 | |
---|
| 914 | writeExpression(os, lp.row(it)); |
---|
| 915 | |
---|
| 916 | if (upper != LpSolverBase::INF) { |
---|
| 917 | os << "<= " << upper << " "; |
---|
| 918 | } |
---|
| 919 | } else { |
---|
[2363] | 920 | |
---|
[2364] | 921 | writeExpression(os, lp.row(it)); |
---|
| 922 | os << "== " << upper << " "; |
---|
| 923 | |
---|
| 924 | } |
---|
[2363] | 925 | |
---|
[2364] | 926 | os << std::endl; |
---|
| 927 | } |
---|
[2363] | 928 | |
---|
[2364] | 929 | os << "bounds" << std::endl; |
---|
| 930 | |
---|
| 931 | for (LpSolverBase::ColIt it(lp); it != INVALID; ++it) { |
---|
| 932 | double lower = lp.colLowerBound(it); |
---|
| 933 | double upper = lp.colUpperBound(it); |
---|
| 934 | if (lower == -LpSolverBase::INF && upper == LpSolverBase::INF) |
---|
| 935 | continue; |
---|
| 936 | os << " "; |
---|
[2363] | 937 | |
---|
[2364] | 938 | if (lower != upper) { |
---|
| 939 | if (lower != -LpSolverBase::INF) { |
---|
| 940 | os << lower << " <= "; |
---|
| 941 | } |
---|
| 942 | |
---|
[2368] | 943 | os << lp.colName(it) << " "; |
---|
[2364] | 944 | |
---|
| 945 | if (upper != LpSolverBase::INF) { |
---|
| 946 | os << "<= " << upper << " "; |
---|
| 947 | } |
---|
| 948 | } else { |
---|
[2368] | 949 | os << lp.colName(it) << " == " << upper << " "; |
---|
[2364] | 950 | } |
---|
| 951 | os << std::endl; |
---|
| 952 | } |
---|
[2363] | 953 | |
---|
[2364] | 954 | os << "objective" << std::endl; |
---|
| 955 | os << " "; |
---|
[2369] | 956 | if (lp.isMin()) { |
---|
[2364] | 957 | os << "min "; |
---|
| 958 | } else { |
---|
| 959 | os << "max "; |
---|
| 960 | } |
---|
| 961 | writeExpression(os, lp.obj()); |
---|
| 962 | os << std::endl; |
---|
| 963 | } |
---|
| 964 | |
---|
[2363] | 965 | |
---|
[2364] | 966 | private: |
---|
[2363] | 967 | |
---|
[2368] | 968 | const LpSolverBase& lp; |
---|
[2364] | 969 | std::string name; |
---|
| 970 | }; |
---|
[2363] | 971 | |
---|
[2316] | 972 | } |
---|
| 973 | |
---|
| 974 | #endif |
---|