* 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
///\brief Demonstrating graph input and output
/// This program gives an example of how to load a directed graph from
/// an \ref lgf-format "LGF" file with the \ref lemon::DigraphReader
/// "DigraphReader" class.
/// The \c "digraph.lgf" file:
/// And the program which reads it:
#include <lemon/smart_graph.h>
#include <lemon/lgf_reader.h>
#include <lemon/lgf_writer.h>
SmartDigraph::ArcMap<int> cap(g);
digraphReader("digraph.lgf", g). // 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
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(std::cout, 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'