lemon/dimacs.h
author Alpar Juttner <alpar@cs.elte.hu>
Sat, 06 Mar 2010 14:35:12 +0000
changeset 956 141f9c0db4a3
parent 631 33c6b6e755cd
child 1270 dceba191c00d
child 1374 00769a5f0f5d
permissions -rw-r--r--
Unify the sources (#339)
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/* -*- mode: C++; indent-tabs-mode: nil; -*-
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 *
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 * This file is a part of LEMON, a generic C++ optimization library.
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 *
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 * Copyright (C) 2003-2010
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 * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
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 * (Egervary Research Group on Combinatorial Optimization, EGRES).
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 *
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 * Permission to use, modify and distribute this software is granted
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 * provided that this copyright notice appears in all copies. For
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 * precise terms see the accompanying LICENSE file.
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 *
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 * This software is provided "AS IS" with no warranty of any kind,
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 * express or implied, and with no claim as to its suitability for any
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 * purpose.
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 *
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 */
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#ifndef LEMON_DIMACS_H
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#define LEMON_DIMACS_H
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#include <iostream>
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#include <string>
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#include <vector>
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#include <limits>
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#include <lemon/maps.h>
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#include <lemon/error.h>
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/// \ingroup dimacs_group
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/// \file
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/// \brief DIMACS file format reader.
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namespace lemon {
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  /// \addtogroup dimacs_group
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  /// @{
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  /// DIMACS file type descriptor.
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  struct DimacsDescriptor
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  {
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    ///\brief DIMACS file type enum
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    ///
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    ///DIMACS file type enum.
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    enum Type {
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      NONE,  ///< Undefined type.
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      MIN,   ///< DIMACS file type for minimum cost flow problems.
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      MAX,   ///< DIMACS file type for maximum flow problems.
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      SP,    ///< DIMACS file type for shostest path problems.
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      MAT    ///< DIMACS file type for plain graphs and matching problems.
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    };
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    ///The file type
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    Type type;
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    ///The number of nodes in the graph
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    int nodeNum;
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    ///The number of edges in the graph
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    int edgeNum;
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    int lineShift;
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    ///Constructor. It sets the type to \c NONE.
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    DimacsDescriptor() : type(NONE) {}
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  };
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  ///Discover the type of a DIMACS file
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  ///This function starts seeking the beginning of the given file for the
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  ///problem type and size info.
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  ///The found data is returned in a special struct that can be evaluated
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  ///and passed to the appropriate reader function.
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  DimacsDescriptor dimacsType(std::istream& is)
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  {
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    DimacsDescriptor r;
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    std::string problem,str;
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    char c;
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    r.lineShift=0;
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    while (is >> c)
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      switch(c)
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        {
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        case 'p':
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          if(is >> problem >> r.nodeNum >> r.edgeNum)
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            {
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              getline(is, str);
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              r.lineShift++;
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              if(problem=="min") r.type=DimacsDescriptor::MIN;
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              else if(problem=="max") r.type=DimacsDescriptor::MAX;
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              else if(problem=="sp") r.type=DimacsDescriptor::SP;
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              else if(problem=="mat") r.type=DimacsDescriptor::MAT;
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              else throw FormatError("Unknown problem type");
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              return r;
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            }
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          else
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            {
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              throw FormatError("Missing or wrong problem type declaration.");
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            }
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          break;
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        case 'c':
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          getline(is, str);
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          r.lineShift++;
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          break;
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        default:
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          throw FormatError("Unknown DIMACS declaration.");
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        }
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    throw FormatError("Missing problem type declaration.");
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  }
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  /// \brief DIMACS minimum cost flow reader function.
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  ///
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  /// This function reads a minimum cost flow instance from DIMACS format,
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  /// i.e. from a DIMACS file having a line starting with
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  /// \code
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  ///   p min
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  /// \endcode
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  /// At the beginning, \c g is cleared by \c g.clear(). The supply
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  /// amount of the nodes are written to the \c supply node map
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  /// (they are signed values). The lower bounds, capacities and costs
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  /// of the arcs are written to the \c lower, \c capacity and \c cost
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  /// arc maps.
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  ///
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  /// If the capacity of an arc is less than the lower bound, it will
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  /// be set to "infinite" instead. The actual value of "infinite" is
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  /// contolled by the \c infty parameter. If it is 0 (the default value),
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  /// \c std::numeric_limits<Capacity>::infinity() will be used if available,
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  /// \c std::numeric_limits<Capacity>::max() otherwise. If \c infty is set to
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  /// a non-zero value, that value will be used as "infinite".
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  ///
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  /// If the file type was previously evaluated by dimacsType(), then
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  /// the descriptor struct should be given by the \c dest parameter.
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  template <typename Digraph, typename LowerMap,
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            typename CapacityMap, typename CostMap,
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            typename SupplyMap>
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  void readDimacsMin(std::istream& is,
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                     Digraph &g,
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                     LowerMap& lower,
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                     CapacityMap& capacity,
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                     CostMap& cost,
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                     SupplyMap& supply,
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                     typename CapacityMap::Value infty = 0,
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                     DimacsDescriptor desc=DimacsDescriptor())
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  {
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    g.clear();
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    std::vector<typename Digraph::Node> nodes;
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    typename Digraph::Arc e;
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    std::string problem, str;
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    char c;
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    int i, j;
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    if(desc.type==DimacsDescriptor::NONE) desc=dimacsType(is);
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    if(desc.type!=DimacsDescriptor::MIN)
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      throw FormatError("Problem type mismatch");
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    nodes.resize(desc.nodeNum + 1);
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    for (int k = 1; k <= desc.nodeNum; ++k) {
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      nodes[k] = g.addNode();
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      supply.set(nodes[k], 0);
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    }
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    typename SupplyMap::Value sup;
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    typename CapacityMap::Value low;
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    typename CapacityMap::Value cap;
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    typename CostMap::Value co;
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    typedef typename CapacityMap::Value Capacity;
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    if(infty==0)
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      infty = std::numeric_limits<Capacity>::has_infinity ?
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        std::numeric_limits<Capacity>::infinity() :
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        std::numeric_limits<Capacity>::max();
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    while (is >> c) {
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      switch (c) {
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      case 'c': // comment line
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        getline(is, str);
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        break;
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      case 'n': // node definition line
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        is >> i >> sup;
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        getline(is, str);
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        supply.set(nodes[i], sup);
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        break;
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      case 'a': // arc definition line
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        is >> i >> j >> low >> cap >> co;
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        getline(is, str);
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        e = g.addArc(nodes[i], nodes[j]);
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        lower.set(e, low);
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        if (cap >= low)
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          capacity.set(e, cap);
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        else
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          capacity.set(e, infty);
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        cost.set(e, co);
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        break;
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      }
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    }
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  }
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  template<typename Digraph, typename CapacityMap>
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  void _readDimacs(std::istream& is,
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                   Digraph &g,
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                   CapacityMap& capacity,
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                   typename Digraph::Node &s,
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                   typename Digraph::Node &t,
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                   typename CapacityMap::Value infty = 0,
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                   DimacsDescriptor desc=DimacsDescriptor()) {
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    g.clear();
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    s=t=INVALID;
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    std::vector<typename Digraph::Node> nodes;
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    typename Digraph::Arc e;
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    char c, d;
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    int i, j;
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    typename CapacityMap::Value _cap;
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    std::string str;
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    nodes.resize(desc.nodeNum + 1);
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    for (int k = 1; k <= desc.nodeNum; ++k) {
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      nodes[k] = g.addNode();
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    }
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    typedef typename CapacityMap::Value Capacity;
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    if(infty==0)
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      infty = std::numeric_limits<Capacity>::has_infinity ?
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        std::numeric_limits<Capacity>::infinity() :
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        std::numeric_limits<Capacity>::max();
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    while (is >> c) {
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      switch (c) {
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      case 'c': // comment line
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        getline(is, str);
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        break;
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      case 'n': // node definition line
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        if (desc.type==DimacsDescriptor::SP) { // shortest path problem
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          is >> i;
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          getline(is, str);
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          s = nodes[i];
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        }
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        if (desc.type==DimacsDescriptor::MAX) { // max flow problem
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          is >> i >> d;
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          getline(is, str);
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          if (d == 's') s = nodes[i];
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          if (d == 't') t = nodes[i];
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        }
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        break;
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      case 'a': // arc definition line
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        if (desc.type==DimacsDescriptor::SP) {
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          is >> i >> j >> _cap;
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          getline(is, str);
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          e = g.addArc(nodes[i], nodes[j]);
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          capacity.set(e, _cap);
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        }
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        else if (desc.type==DimacsDescriptor::MAX) {
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          is >> i >> j >> _cap;
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          getline(is, str);
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          e = g.addArc(nodes[i], nodes[j]);
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          if (_cap >= 0)
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            capacity.set(e, _cap);
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          else
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            capacity.set(e, infty);
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        }
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        else {
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          is >> i >> j;
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          getline(is, str);
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          g.addArc(nodes[i], nodes[j]);
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        }
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        break;
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      }
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    }
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  }
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  /// \brief DIMACS maximum flow reader function.
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  ///
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  /// This function reads a maximum flow instance from DIMACS format,
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  /// i.e. from a DIMACS file having a line starting with
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  /// \code
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  ///   p max
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  /// \endcode
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  /// At the beginning, \c g is cleared by \c g.clear(). The arc
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  /// capacities are written to the \c capacity arc map and \c s and
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  /// \c t are set to the source and the target nodes.
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  ///
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  /// If the capacity of an arc is negative, it will
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  /// be set to "infinite" instead. The actual value of "infinite" is
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  /// contolled by the \c infty parameter. If it is 0 (the default value),
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  /// \c std::numeric_limits<Capacity>::infinity() will be used if available,
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  /// \c std::numeric_limits<Capacity>::max() otherwise. If \c infty is set to
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  /// a non-zero value, that value will be used as "infinite".
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  ///
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  /// If the file type was previously evaluated by dimacsType(), then
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  /// the descriptor struct should be given by the \c dest parameter.
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  template<typename Digraph, typename CapacityMap>
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  void readDimacsMax(std::istream& is,
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                     Digraph &g,
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                     CapacityMap& capacity,
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                     typename Digraph::Node &s,
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                     typename Digraph::Node &t,
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                     typename CapacityMap::Value infty = 0,
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                     DimacsDescriptor desc=DimacsDescriptor()) {
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    if(desc.type==DimacsDescriptor::NONE) desc=dimacsType(is);
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    if(desc.type!=DimacsDescriptor::MAX)
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      throw FormatError("Problem type mismatch");
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    _readDimacs(is,g,capacity,s,t,infty,desc);
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  }
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  /// \brief DIMACS shortest path reader function.
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  ///
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  /// This function reads a shortest path instance from DIMACS format,
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  /// i.e. from a DIMACS file having a line starting with
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  /// \code
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  ///   p sp
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  /// \endcode
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  /// At the beginning, \c g is cleared by \c g.clear(). The arc
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  /// lengths are written to the \c length arc map and \c s is set to the
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  /// source node.
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  ///
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  /// If the file type was previously evaluated by dimacsType(), then
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  /// the descriptor struct should be given by the \c dest parameter.
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  template<typename Digraph, typename LengthMap>
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  void readDimacsSp(std::istream& is,
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                    Digraph &g,
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                    LengthMap& length,
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                    typename Digraph::Node &s,
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                    DimacsDescriptor desc=DimacsDescriptor()) {
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    typename Digraph::Node t;
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    if(desc.type==DimacsDescriptor::NONE) desc=dimacsType(is);
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    if(desc.type!=DimacsDescriptor::SP)
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      throw FormatError("Problem type mismatch");
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    _readDimacs(is, g, length, s, t, 0, desc);
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  }
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  /// \brief DIMACS capacitated digraph reader function.
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  ///
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  /// This function reads an arc capacitated digraph instance from
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  /// DIMACS 'max' or 'sp' format.
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  /// At the beginning, \c g is cleared by \c g.clear()
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  /// and the arc capacities/lengths are written to the \c capacity
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  /// arc map.
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  ///
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  /// In case of the 'max' format, if the capacity of an arc is negative,
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  /// it will
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  /// be set to "infinite" instead. The actual value of "infinite" is
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  /// contolled by the \c infty parameter. If it is 0 (the default value),
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  /// \c std::numeric_limits<Capacity>::infinity() will be used if available,
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  /// \c std::numeric_limits<Capacity>::max() otherwise. If \c infty is set to
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  /// a non-zero value, that value will be used as "infinite".
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  ///
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  /// If the file type was previously evaluated by dimacsType(), then
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  /// the descriptor struct should be given by the \c dest parameter.
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  template<typename Digraph, typename CapacityMap>
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  void readDimacsCap(std::istream& is,
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                     Digraph &g,
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                     CapacityMap& capacity,
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                     typename CapacityMap::Value infty = 0,
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                     DimacsDescriptor desc=DimacsDescriptor()) {
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    typename Digraph::Node u,v;
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    if(desc.type==DimacsDescriptor::NONE) desc=dimacsType(is);
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    if(desc.type!=DimacsDescriptor::MAX || desc.type!=DimacsDescriptor::SP)
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      throw FormatError("Problem type mismatch");
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    _readDimacs(is, g, capacity, u, v, infty, desc);
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  }
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  template<typename Graph>
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  typename enable_if<lemon::UndirectedTagIndicator<Graph>,void>::type
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  _addArcEdge(Graph &g, typename Graph::Node s, typename Graph::Node t,
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              dummy<0> = 0)
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  {
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    g.addEdge(s,t);
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  }
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  template<typename Graph>
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  typename disable_if<lemon::UndirectedTagIndicator<Graph>,void>::type
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  _addArcEdge(Graph &g, typename Graph::Node s, typename Graph::Node t,
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              dummy<1> = 1)
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  {
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    g.addArc(s,t);
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  }
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  /// \brief DIMACS plain (di)graph reader function.
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  ///
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  /// This function reads a plain (di)graph without any designated nodes
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  /// and maps (e.g. a matching instance) from DIMACS format, i.e. from
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  /// DIMACS files having a line starting with
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  /// \code
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  ///   p mat
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  /// \endcode
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  /// At the beginning, \c g is cleared by \c g.clear().
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  ///
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  /// If the file type was previously evaluated by dimacsType(), then
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  /// the descriptor struct should be given by the \c dest parameter.
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  template<typename Graph>
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  void readDimacsMat(std::istream& is, Graph &g,
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                     DimacsDescriptor desc=DimacsDescriptor())
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  {
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   382
    if(desc.type==DimacsDescriptor::NONE) desc=dimacsType(is);
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   383
    if(desc.type!=DimacsDescriptor::MAT)
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   384
      throw FormatError("Problem type mismatch");
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   385
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   386
    g.clear();
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   387
    std::vector<typename Graph::Node> nodes;
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   388
    char c;
alpar@572
   389
    int i, j;
alpar@572
   390
    std::string str;
alpar@572
   391
    nodes.resize(desc.nodeNum + 1);
alpar@572
   392
    for (int k = 1; k <= desc.nodeNum; ++k) {
alpar@572
   393
      nodes[k] = g.addNode();
alpar@572
   394
    }
alpar@956
   395
alpar@572
   396
    while (is >> c) {
alpar@572
   397
      switch (c) {
alpar@572
   398
      case 'c': // comment line
alpar@572
   399
        getline(is, str);
alpar@572
   400
        break;
alpar@572
   401
      case 'n': // node definition line
alpar@572
   402
        break;
alpar@608
   403
      case 'a': // arc definition line
alpar@572
   404
        is >> i >> j;
alpar@572
   405
        getline(is, str);
alpar@572
   406
        _addArcEdge(g,nodes[i], nodes[j]);
alpar@572
   407
        break;
alpar@572
   408
      }
alpar@572
   409
    }
alpar@400
   410
  }
alpar@400
   411
alpar@400
   412
  /// DIMACS plain digraph writer function.
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   413
  ///
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   414
  /// This function writes a digraph without any designated nodes and
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   415
  /// maps into DIMACS format, i.e. into DIMACS file having a line
alpar@400
   416
  /// starting with
alpar@400
   417
  /// \code
alpar@400
   418
  ///   p mat
alpar@400
   419
  /// \endcode
alpar@402
   420
  /// If \c comment is not empty, then it will be printed in the first line
alpar@402
   421
  /// prefixed by 'c'.
alpar@400
   422
  template<typename Digraph>
alpar@402
   423
  void writeDimacsMat(std::ostream& os, const Digraph &g,
alpar@402
   424
                      std::string comment="") {
alpar@400
   425
    typedef typename Digraph::NodeIt NodeIt;
alpar@400
   426
    typedef typename Digraph::ArcIt ArcIt;
alpar@400
   427
alpar@463
   428
    if(!comment.empty())
alpar@402
   429
      os << "c " << comment << std::endl;
alpar@400
   430
    os << "p mat " << g.nodeNum() << " " << g.arcNum() << std::endl;
alpar@400
   431
alpar@400
   432
    typename Digraph::template NodeMap<int> nodes(g);
alpar@400
   433
    int i = 1;
alpar@400
   434
    for(NodeIt v(g); v != INVALID; ++v) {
alpar@400
   435
      nodes.set(v, i);
alpar@400
   436
      ++i;
alpar@400
   437
    }
alpar@400
   438
    for(ArcIt e(g); e != INVALID; ++e) {
alpar@400
   439
      os << "a " << nodes[g.source(e)] << " " << nodes[g.target(e)]
alpar@400
   440
         << std::endl;
alpar@400
   441
    }
alpar@400
   442
  }
alpar@400
   443
alpar@400
   444
  /// @}
alpar@400
   445
alpar@400
   446
} //namespace lemon
alpar@400
   447
alpar@400
   448
#endif //LEMON_DIMACS_H