/* -*- 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.

  *

  */

 ///\ingroup demos

 ///\file

 ///\brief Demonstrating graph input and output

 ///

 /// This program gives an example of how to read and write a digraph

 /// and additional maps from/to a stream or a file using the

 /// \ref lgf-format "LGF" format.

 ///

 /// The \c "digraph.lgf" file:

 /// \include digraph.lgf

 ///

 /// And the program which reads it and prints the digraph to the

 /// standard output:

 /// \include lgf_demo.cc

 #include <iostream>

 #include <lemon/smart_graph.h>

 #include <lemon/lgf_reader.h>

 #include <lemon/lgf_writer.h>

 using namespace lemon;

 int main() {

   SmartDigraph g;

   SmartDigraph::ArcMap<int> cap(g);

   SmartDigraph::Node s, t;

   try {

     digraphReader(g, "digraph.lgf"). // read the directed graph into g

       arcMap("capacity", cap).       // read the 'capacity' arc map into cap

       node("source", s).             // read 'source' node to s

       node("target", t).             // read 'target' node to t

       run();

   } catch (Exception& error) { // check if there was any error

     std::cerr << "Error: " << error.what() << std::endl;

     return -1;

   }

   std::cout << "A digraph is read from 'digraph.lgf'." << std::endl;

   std::cout << "Number of nodes: " << countNodes(g) << std::endl;

   std::cout << "Number of arcs: " << countArcs(g) << std::endl;

   std::cout << "We can write it to the standard output:" << std::endl;

   digraphWriter(g).                // write g to the standard output

     arcMap("capacity", cap).       // write cap into 'capacity'

     node("source", s).             // write s to 'source'

     node("target", t).             // write t to 'target'

     run();

   return 0;

 }