/* -*- mode: C++; indent-tabs-mode: nil; -*-

  *

  * This file is a part of LEMON, a generic C++ optimization library.

  *

  * Copyright (C) 2003-2008

  * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport

  * (Egervary Research Group on Combinatorial Optimization, EGRES).

  *

  * Permission to use, modify and distribute this software is granted

  * provided that this copyright notice appears in all copies. For

  * precise terms see the accompanying LICENSE file.

  *

  * This software is provided "AS IS" with no warranty of any kind,

  * express or implied, and with no claim as to its suitability for any

  * purpose.

  *

  */

 #ifndef LEMON_DIMACS_H

 #define LEMON_DIMACS_H

 #include <iostream>

 #include <string>

 #include <vector>

 #include <lemon/maps.h>

 /// \ingroup dimacs_group

 /// \file

 /// \brief DIMACS file format reader.

 namespace lemon {

   ///@defgroup dimacs_group DIMACS format

   ///\brief Read and write files in DIMACS format

   ///

   ///Tools to read a digraph from or write it to a file in DIMACS format

   ///data

   ///\ingroup io_group

   /// \addtogroup dimacs_group

   /// @{

   /// DIMACS min cost flow reader function.

   ///

   /// This function reads a min cost flow instance from DIMACS format,

   /// i.e. from DIMACS files having a line starting with

   /// \code

   ///   p min

   /// \endcode

   /// At the beginning \c g is cleared by \c g.clear(). The supply

   /// amount of the nodes are written to \c supply (signed). The

   /// lower bounds, capacities and costs of the arcs are written to

   /// \c lower, \c capacity and \c cost.

   template <typename Digraph, typename LowerMap,

     typename CapacityMap, typename CostMap,

     typename SupplyMap>

   void readDimacs( std::istream& is,

                    Digraph &g,

                    LowerMap& lower,

                    CapacityMap& capacity,

                    CostMap& cost,

                    SupplyMap& supply )

   {

     g.clear();

     std::vector<typename Digraph::Node> nodes;

     typename Digraph::Arc e;

     std::string problem, str;

     char c;

     int n, m;

     int i, j;

     typename SupplyMap::Value sup;

     typename CapacityMap::Value low;

     typename CapacityMap::Value cap;

     typename CostMap::Value co;

     while (is >> c) {

       switch (c) {

       case 'c': // comment line

         getline(is, str);

         break;

       case 'p': // problem definition line

         is >> problem >> n >> m;

         getline(is, str);

         if (problem != "min") return;

         nodes.resize(n + 1);

         for (int k = 1; k <= n; ++k) {

           nodes[k] = g.addNode();

           supply.set(nodes[k], 0);

         }

         break;

       case 'n': // node definition line

         is >> i >> sup;

         getline(is, str);

         supply.set(nodes[i], sup);

         break;

       case 'a': // arc (arc) definition line

         is >> i >> j >> low >> cap >> co;

         getline(is, str);

         e = g.addArc(nodes[i], nodes[j]);

         lower.set(e, low);

         if (cap >= 0)

           capacity.set(e, cap);

         else

           capacity.set(e, -1);

         cost.set(e, co);

         break;

       }

     }

   }

   /// DIMACS max flow reader function.

   ///

   /// This function reads a max flow instance from DIMACS format,

   /// i.e. from DIMACS files having a line starting with

   /// \code

   ///   p max

   /// \endcode

   /// At the beginning \c g is cleared by \c g.clear(). The arc

   /// capacities are written to \c capacity and \c s and \c t are

   /// set to the source and the target nodes.

   template<typename Digraph, typename CapacityMap>

   void readDimacs(std::istream& is, Digraph &g, CapacityMap& capacity,

                   typename Digraph::Node &s, typename Digraph::Node &t) {

     g.clear();

     std::vector<typename Digraph::Node> nodes;

     typename Digraph::Arc e;

     std::string problem;

     char c, d;

     int n, m;

     int i, j;

     typename CapacityMap::Value _cap;

     std::string str;

     while (is >> c) {

       switch (c) {

       case 'c': // comment line

         getline(is, str);

         break;

       case 'p': // problem definition line

         is >> problem >> n >> m;

         getline(is, str);

         nodes.resize(n + 1);

         for (int k = 1; k <= n; ++k)

           nodes[k] = g.addNode();

         break;

       case 'n': // node definition line

         if (problem == "sp") { // shortest path problem

           is >> i;

           getline(is, str);

           s = nodes[i];

         }

         if (problem == "max") { // max flow problem

           is >> i >> d;

           getline(is, str);

           if (d == 's') s = nodes[i];

           if (d == 't') t = nodes[i];

         }

         break;

       case 'a': // arc (arc) definition line

         if (problem == "max" || problem == "sp") {

           is >> i >> j >> _cap;

           getline(is, str);

           e = g.addArc(nodes[i], nodes[j]);

           capacity.set(e, _cap);

         } else {

           is >> i >> j;

           getline(is, str);

           g.addArc(nodes[i], nodes[j]);

         }

         break;

       }

     }

   }

   /// DIMACS shortest path reader function.

   ///

   /// This function reads a shortest path instance from DIMACS format,

   /// i.e. from DIMACS files having a line starting with

   /// \code

   ///   p sp

   /// \endcode

   /// At the beginning \c g is cleared by \c g.clear(). The arc

   /// capacities are written to \c capacity and \c s is set to the

   /// source node.

   template<typename Digraph, typename CapacityMap>

   void readDimacs(std::istream& is, Digraph &g, CapacityMap& capacity,

                   typename Digraph::Node &s) {

     readDimacs(is, g, capacity, s, s);

   }

   /// DIMACS capacitated digraph reader function.

   ///

   /// This function reads an arc capacitated digraph instance from

   /// DIMACS format. At the beginning \c g is cleared by \c g.clear()

   /// and the arc capacities are written to \c capacity.

   template<typename Digraph, typename CapacityMap>

   void readDimacs(std::istream& is, Digraph &g, CapacityMap& capacity) {

     typename Digraph::Node u;

     readDimacs(is, g, capacity, u, u);

   }

   /// DIMACS plain digraph reader function.

   ///

   /// This function reads a digraph without any designated nodes and

   /// maps from DIMACS format, i.e. from DIMACS files having a line

   /// starting with

   /// \code

   ///   p mat

   /// \endcode

   /// At the beginning \c g is cleared by \c g.clear().

   template<typename Digraph>

   void readDimacs(std::istream& is, Digraph &g) {

     typename Digraph::Node u;

     NullMap<typename Digraph::Arc, int> n;

     readDimacs(is, g, n, u, u);

   }

   /// DIMACS plain digraph writer function.

   ///

   /// This function writes a digraph without any designated nodes and

   /// maps into DIMACS format, i.e. into DIMACS file having a line

   /// starting with

   /// \code

   ///   p mat

   /// \endcode

   template<typename Digraph>

   void writeDimacs(std::ostream& os, const Digraph &g) {

     typedef typename Digraph::NodeIt NodeIt;

     typedef typename Digraph::ArcIt ArcIt;

     os << "c matching problem" << std::endl;

     os << "p mat " << g.nodeNum() << " " << g.arcNum() << std::endl;

     typename Digraph::template NodeMap<int> nodes(g);

     int i = 1;

     for(NodeIt v(g); v != INVALID; ++v) {

       nodes.set(v, i);

       ++i;

     }

     for(ArcIt e(g); e != INVALID; ++e) {

       os << "a " << nodes[g.source(e)] << " " << nodes[g.target(e)]

          << std::endl;

     }

   }

   /// @}

 } //namespace lemon

 #endif //LEMON_DIMACS_H