COIN-OR::LEMON - Graph Library

source: lemon-1.2/lemon/dimacs.h @ 386:9d1faab5e0f1

Last change on this file since 386:9d1faab5e0f1 was 386:9d1faab5e0f1, checked in by Alpar Juttner <alpar@…>, 11 years ago

Give different names to the different DIMACS readers

File size: 7.3 KB
Line 
1/* -*- mode: C++; indent-tabs-mode: nil; -*-
2 *
3 * This file is a part of LEMON, a generic C++ optimization library.
4 *
5 * Copyright (C) 2003-2008
6 * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
7 * (Egervary Research Group on Combinatorial Optimization, EGRES).
8 *
9 * Permission to use, modify and distribute this software is granted
10 * provided that this copyright notice appears in all copies. For
11 * precise terms see the accompanying LICENSE file.
12 *
13 * This software is provided "AS IS" with no warranty of any kind,
14 * express or implied, and with no claim as to its suitability for any
15 * purpose.
16 *
17 */
18
19#ifndef LEMON_DIMACS_H
20#define LEMON_DIMACS_H
21
22#include <iostream>
23#include <string>
24#include <vector>
25#include <lemon/maps.h>
26
27/// \ingroup dimacs_group
28/// \file
29/// \brief DIMACS file format reader.
30
31namespace lemon {
32
33  ///@defgroup dimacs_group DIMACS format
34  ///\brief Read and write files in DIMACS format
35  ///
36  ///Tools to read a digraph from or write it to a file in DIMACS format
37  ///data
38  ///\ingroup io_group
39
40  /// \addtogroup dimacs_group
41  /// @{
42
43  /// DIMACS min cost flow reader function.
44  ///
45  /// This function reads a min cost flow instance from DIMACS format,
46  /// i.e. from DIMACS files having a line starting with
47  /// \code
48  ///   p min
49  /// \endcode
50  /// At the beginning \c g is cleared by \c g.clear(). The supply
51  /// amount of the nodes are written to \c supply (signed). The
52  /// lower bounds, capacities and costs of the arcs are written to
53  /// \c lower, \c capacity and \c cost.
54  template <typename Digraph, typename LowerMap,
55    typename CapacityMap, typename CostMap,
56    typename SupplyMap>
57  void readDimacsMin( std::istream& is,
58                   Digraph &g,
59                   LowerMap& lower,
60                   CapacityMap& capacity,
61                   CostMap& cost,
62                   SupplyMap& supply )
63  {
64    g.clear();
65    std::vector<typename Digraph::Node> nodes;
66    typename Digraph::Arc e;
67    std::string problem, str;
68    char c;
69    int n, m;
70    int i, j;
71    typename SupplyMap::Value sup;
72    typename CapacityMap::Value low;
73    typename CapacityMap::Value cap;
74    typename CostMap::Value co;
75    while (is >> c) {
76      switch (c) {
77      case 'c': // comment line
78        getline(is, str);
79        break;
80      case 'p': // problem definition line
81        is >> problem >> n >> m;
82        getline(is, str);
83        if (problem != "min") return;
84        nodes.resize(n + 1);
85        for (int k = 1; k <= n; ++k) {
86          nodes[k] = g.addNode();
87          supply.set(nodes[k], 0);
88        }
89        break;
90      case 'n': // node definition line
91        is >> i >> sup;
92        getline(is, str);
93        supply.set(nodes[i], sup);
94        break;
95      case 'a': // arc (arc) definition line
96        is >> i >> j >> low >> cap >> co;
97        getline(is, str);
98        e = g.addArc(nodes[i], nodes[j]);
99        lower.set(e, low);
100        if (cap >= 0)
101          capacity.set(e, cap);
102        else
103          capacity.set(e, -1);
104        cost.set(e, co);
105        break;
106      }
107    }
108  }
109
110  /// DIMACS max flow reader function.
111  ///
112  /// This function reads a max flow instance from DIMACS format,
113  /// i.e. from DIMACS files having a line starting with
114  /// \code
115  ///   p max
116  /// \endcode
117  /// At the beginning \c g is cleared by \c g.clear(). The arc
118  /// capacities are written to \c capacity and \c s and \c t are
119  /// set to the source and the target nodes.
120  template<typename Digraph, typename CapacityMap>
121  void readDimacsMax(std::istream& is, Digraph &g, CapacityMap& capacity,
122                  typename Digraph::Node &s, typename Digraph::Node &t) {
123    g.clear();
124    std::vector<typename Digraph::Node> nodes;
125    typename Digraph::Arc e;
126    std::string problem;
127    char c, d;
128    int n, m;
129    int i, j;
130    typename CapacityMap::Value _cap;
131    std::string str;
132    while (is >> c) {
133      switch (c) {
134      case 'c': // comment line
135        getline(is, str);
136        break;
137      case 'p': // problem definition line
138        is >> problem >> n >> m;
139        getline(is, str);
140        nodes.resize(n + 1);
141        for (int k = 1; k <= n; ++k)
142          nodes[k] = g.addNode();
143        break;
144      case 'n': // node definition line
145        if (problem == "sp") { // shortest path problem
146          is >> i;
147          getline(is, str);
148          s = nodes[i];
149        }
150        if (problem == "max") { // max flow problem
151          is >> i >> d;
152          getline(is, str);
153          if (d == 's') s = nodes[i];
154          if (d == 't') t = nodes[i];
155        }
156        break;
157      case 'a': // arc (arc) definition line
158        if (problem == "max" || problem == "sp") {
159          is >> i >> j >> _cap;
160          getline(is, str);
161          e = g.addArc(nodes[i], nodes[j]);
162          capacity.set(e, _cap);
163        } else {
164          is >> i >> j;
165          getline(is, str);
166          g.addArc(nodes[i], nodes[j]);
167        }
168        break;
169      }
170    }
171  }
172
173  /// DIMACS shortest path reader function.
174  ///
175  /// This function reads a shortest path instance from DIMACS format,
176  /// i.e. from DIMACS files having a line starting with
177  /// \code
178  ///   p sp
179  /// \endcode
180  /// At the beginning \c g is cleared by \c g.clear(). The arc
181  /// capacities are written to \c capacity and \c s is set to the
182  /// source node.
183  template<typename Digraph, typename CapacityMap>
184  void readDimacsSp(std::istream& is, Digraph &g, CapacityMap& capacity,
185                  typename Digraph::Node &s) {
186    typename Digraph::Node t;
187    readDimacsMax(is, g, capacity, s, t);
188  }
189
190  /// DIMACS capacitated digraph reader function.
191  ///
192  /// This function reads an arc capacitated digraph instance from
193  /// DIMACS format. At the beginning \c g is cleared by \c g.clear()
194  /// and the arc capacities are written to \c capacity.
195  template<typename Digraph, typename CapacityMap>
196  void readDimacsMax(std::istream& is, Digraph &g, CapacityMap& capacity) {
197    typename Digraph::Node u,v;
198    readDimacsMax(is, g, capacity, u, v);
199  }
200
201  /// DIMACS plain digraph reader function.
202  ///
203  /// This function reads a digraph without any designated nodes and
204  /// maps from DIMACS format, i.e. from DIMACS files having a line
205  /// starting with
206  /// \code
207  ///   p mat
208  /// \endcode
209  /// At the beginning \c g is cleared by \c g.clear().
210  template<typename Digraph>
211  void readDimacsMat(std::istream& is, Digraph &g) {
212    typename Digraph::Node u,v;
213    NullMap<typename Digraph::Arc, int> n;
214    readDimacsMax(is, g, n, u, v);
215  }
216
217  /// DIMACS plain digraph writer function.
218  ///
219  /// This function writes a digraph without any designated nodes and
220  /// maps into DIMACS format, i.e. into DIMACS file having a line
221  /// starting with
222  /// \code
223  ///   p mat
224  /// \endcode
225  template<typename Digraph>
226  void writeDimacsMat(std::ostream& os, const Digraph &g) {
227    typedef typename Digraph::NodeIt NodeIt;
228    typedef typename Digraph::ArcIt ArcIt;
229
230    os << "c matching problem" << std::endl;
231    os << "p mat " << g.nodeNum() << " " << g.arcNum() << std::endl;
232
233    typename Digraph::template NodeMap<int> nodes(g);
234    int i = 1;
235    for(NodeIt v(g); v != INVALID; ++v) {
236      nodes.set(v, i);
237      ++i;
238    }
239    for(ArcIt e(g); e != INVALID; ++e) {
240      os << "a " << nodes[g.source(e)] << " " << nodes[g.target(e)]
241         << std::endl;
242    }
243  }
244
245  /// @}
246
247} //namespace lemon
248
249#endif //LEMON_DIMACS_H
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