demo/lgf_demo.cc
author Alpar Juttner <alpar@cs.elte.hu>
Sat, 17 May 2008 06:30:02 +0100
changeset 156 e561aa7675de
parent 127 1c9a9e2f7d4d
child 164 00d297da491e
permissions -rw-r--r--
More flexible header names in .lgf + largely improved doc
     1 /* -*- C++ -*-
     2  *
     3  * This file is a part of LEMON, a generic C++ optimization library
     4  *
     5  * Copyright (C) 2003-2008
     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 simple demo program gives an example of how to read and write
    24 /// a graph and additional maps (on the nodes or the edges) from/to a
    25 /// stream. 
    26 ///
    27 /// \include reader_writer_demo.cc
    28 
    29 #include <iostream>
    30 #include <lemon/smart_graph.h>
    31 #include <lemon/lgf_reader.h>
    32 #include <lemon/lgf_writer.h>
    33 #include <lemon/random.h>
    34 
    35 
    36 using namespace lemon;
    37 
    38 int main(int argc, const char *argv[]) {
    39   const int n = argc > 1 ? std::atoi(argv[1]) : 20;
    40   const int e = argc > 2 ? std::atoi(argv[2]) : static_cast<int>(n * std::log(double(n)));
    41   const int m = argc > 3 ? std::atoi(argv[3]) : 100;
    42 
    43   SmartDigraph digraph;
    44 
    45   std::stringstream ss;
    46 
    47   try {
    48 
    49     typedef SmartDigraph Digraph;
    50     typedef Digraph::Node Node;
    51     typedef Digraph::Arc Arc;
    52     typedef Digraph::ArcIt ArcIt;
    53 
    54     typedef Digraph::NodeMap<int> PotentialMap;
    55     typedef Digraph::ArcMap<int> CapacityMap;
    56     typedef Digraph::ArcMap<std::string> NameMap;
    57 
    58     Digraph digraph;
    59     PotentialMap potential(digraph);
    60     CapacityMap capacity(digraph);
    61     NameMap name(digraph);
    62 
    63     std::vector<Node> nodes;
    64     for (int i = 0; i < n; ++i) {
    65       Node node = digraph.addNode();
    66       potential[node] = rnd[m];
    67       nodes.push_back(node);
    68     }
    69 
    70     std::vector<Arc> arcs;
    71     for (int i = 0; i < e; ++i) {
    72       int s = rnd[n];
    73       int t = rnd[n];
    74       int c = rnd[m];
    75       Arc arc = digraph.addArc(nodes[s], nodes[t]);
    76       capacity[arc] = c;
    77       std::ostringstream os;
    78       os << "arc \t" << i << std::endl;
    79       name[arc] = os.str();
    80       arcs.push_back(arc);
    81     }
    82 
    83 
    84     DigraphWriter<Digraph>(ss, digraph).
    85       nodeMap("potential", potential).
    86       arcMap("capacity", capacity).
    87       arcMap("name", name).
    88       node("source", nodes[0]).
    89       node("target", nodes[1]).
    90       arc("bottleneck", arcs[e / 2]).
    91       attribute("creator", "lemon library").
    92       run();
    93 
    94   } catch (DataFormatError& error) {
    95     std::cerr << error.what() << std::endl;
    96   }
    97 
    98   try {
    99 
   100     typedef SmartDigraph Digraph;
   101     typedef Digraph::Node Node;
   102     typedef Digraph::Arc Arc;
   103     typedef Digraph::ArcIt ArcIt;
   104 
   105     typedef Digraph::NodeMap<int> LabelMap;
   106     typedef Digraph::NodeMap<int> PotentialMap;
   107     typedef Digraph::ArcMap<int> CapacityMap;
   108     typedef Digraph::ArcMap<std::string> NameMap;
   109 
   110     Digraph digraph;
   111     LabelMap label(digraph);
   112     PotentialMap potential(digraph);
   113     CapacityMap capacity(digraph);
   114     NameMap name(digraph);
   115 
   116     Node s, t;
   117     Arc a;
   118     
   119     std::string creator;
   120 
   121     for (int i = 0; i < n; ++i) {
   122       Node node = digraph.addNode();
   123       label[node] = i;
   124     }
   125     
   126     DigraphReader<Digraph>(ss, digraph).
   127       useNodes(label).
   128       nodeMap("potential", potential).
   129       arcMap("capacity", capacity).
   130       arcMap("name", name).
   131       node("source", s).
   132       node("target", t).
   133       arc("bottleneck", a).
   134       attribute("creator", creator).
   135       run();
   136 
   137     DigraphWriter<Digraph>(std::cout, digraph).
   138       nodeMap("potential", potential).
   139       arcMap("capacity", capacity).
   140       arcMap("name", name).
   141       node("source", s).
   142       node("target", t).
   143       arc("bottleneck", a).
   144       attribute("creator", creator).
   145       run();
   146 
   147   } catch (DataFormatError& error) {
   148     std::cerr << error.what() << std::endl;
   149   }
   150 
   151 
   152   return 0;
   153 }