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

 *

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

 *

 * Copyright (C) 2003-2009

 * 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;

}