/* -*- C++ -*-

  *

  * 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>

 #include <lemon/bits/invalid.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 graph 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 edges are written to 

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

   ///

   /// \author Marton Makai and Peter Kovacs

   template <typename Graph, typename LowerMap, 

     typename CapacityMap, typename CostMap, 

     typename SupplyMap>

   void readDimacs( std::istream& is,

 		   Graph &g,

 		   LowerMap& lower, 

 		   CapacityMap& capacity, 

 		   CostMap& cost,

 		   SupplyMap& supply )

   {

     g.clear();

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

     typename Graph::Edge 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': // edge (arc) definition line

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

 	getline(is, str);

 	e = g.addEdge(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 edge 

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

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

   ///

   /// \author Marton Makai

   template<typename Graph, typename CapacityMap>

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

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

     g.clear();

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

     typename Graph::Edge 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': // edge (arc) definition line

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

 	  is >> i >> j >> _cap;

 	  getline(is, str);

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

 	  capacity.set(e, _cap);

 	} else {

 	  is >> i >> j;

 	  getline(is, str);

 	  g.addEdge(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 edge

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

   /// source node.

   ///

   /// \author Marton Makai

   template<typename Graph, typename CapacityMap>

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

 		  typename Graph::Node &s) {

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

   }

   /// DIMACS capacitated graph reader function.

   ///

   /// This function reads an edge capacitated graph instance from

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

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

   ///

   /// \author Marton Makai

   template<typename Graph, typename CapacityMap>

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

     typename Graph::Node u;

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

   }

   /// DIMACS plain graph reader function.

   ///

   /// This function reads a graph 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().

   ///

   /// \author Marton Makai

   template<typename Graph>

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

     typename Graph::Node u;

     NullMap<typename Graph::Edge, int> n;

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

   }

   /// DIMACS plain graph writer function.

   ///

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

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

   /// starting with

   /// \code

   ///   p mat

   /// \endcode

   ///

   /// \author Marton Makai

   template<typename Graph>

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

     typedef typename Graph::NodeIt NodeIt;

     typedef typename Graph::EdgeIt EdgeIt;  

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

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

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

     int i = 1;

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

       nodes.set(v, i);

       ++i;

     }    

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

       os << "a " << nodes[g.source(e)] << " " << nodes[g.target(e)] << std::endl; 

     }

   }

   /// @}

 } //namespace lemon

 #endif //LEMON_DIMACS_H