demo/lgf_demo.cc
author Peter Kovacs <kpeter@inf.elte.hu>
Thu, 02 Jul 2009 17:36:29 +0200
changeset 728 e2bdd1a988f3
parent 294 cbe3ec2d59d2
permissions -rw-r--r--
Add a parameter to control arc mixing in NS (#298)
     1 /* -*- mode: C++; indent-tabs-mode: nil; -*-
     2  *
     3  * This file is a part of LEMON, a generic C++ optimization library.
     4  *
     5  * Copyright (C) 2003-2009
     6  * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
     7  * (Egervary Research Group on Combinatorial Optimization, EGRES).
     8  *
     9  * Permission to use, modify and distribute this software is granted
    10  * provided that this copyright notice appears in all copies. For
    11  * precise terms see the accompanying LICENSE file.
    12  *
    13  * This software is provided "AS IS" with no warranty of any kind,
    14  * express or implied, and with no claim as to its suitability for any
    15  * purpose.
    16  *
    17  */
    18 
    19 ///\ingroup demos
    20 ///\file
    21 ///\brief Demonstrating graph input and output
    22 ///
    23 /// This program gives an example of how to read and write a digraph
    24 /// and additional maps from/to a stream or a file using the
    25 /// \ref lgf-format "LGF" format.
    26 ///
    27 /// The \c "digraph.lgf" file:
    28 /// \include digraph.lgf
    29 ///
    30 /// And the program which reads it and prints the digraph to the
    31 /// standard output:
    32 /// \include lgf_demo.cc
    33 
    34 #include <iostream>
    35 #include <lemon/smart_graph.h>
    36 #include <lemon/lgf_reader.h>
    37 #include <lemon/lgf_writer.h>
    38 
    39 using namespace lemon;
    40 
    41 int main() {
    42   SmartDigraph g;
    43   SmartDigraph::ArcMap<int> cap(g);
    44   SmartDigraph::Node s, t;
    45 
    46   try {
    47     digraphReader(g, "digraph.lgf"). // read the directed graph into g
    48       arcMap("capacity", cap).       // read the 'capacity' arc map into cap
    49       node("source", s).             // read 'source' node to s
    50       node("target", t).             // read 'target' node to t
    51       run();
    52   } catch (Exception& error) { // check if there was any error
    53     std::cerr << "Error: " << error.what() << std::endl;
    54     return -1;
    55   }
    56 
    57   std::cout << "A digraph is read from 'digraph.lgf'." << std::endl;
    58   std::cout << "Number of nodes: " << countNodes(g) << std::endl;
    59   std::cout << "Number of arcs: " << countArcs(g) << std::endl;
    60 
    61   std::cout << "We can write it to the standard output:" << std::endl;
    62 
    63   digraphWriter(g).                // write g to the standard output
    64     arcMap("capacity", cap).       // write cap into 'capacity'
    65     node("source", s).             // write s to 'source'
    66     node("target", t).             // write t to 'target'
    67     run();
    68 
    69   return 0;
    70 }