/* -*- C++ -*-

  *

  * 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 LEMON style "Hello World!" program

 ///

 /// This program is intended to be a "Hello World!" program that shows

 /// the very basic notions of the LEMON library: \ref graphs "graphs" and

 /// \ref maps-page "maps". Click on the links to read more about these.

 ///

 /// \include hello_world.cc

 #include <iostream>

 #include <lemon/list_graph.h>

 using namespace lemon;

 typedef ListGraph::Node  Node;

 typedef ListGraph::Edge  Edge;

 int main()

 {

   // Declare the graph itself and a NodeMap, witch will store the characters

   // assigned to the nodes

   ListGraph  graph;

   ListGraph::NodeMap<char>  char_map(graph);

   // Add nodes

   Node  new_node = graph.addNode();

   char_map[new_node] = 'H';

   // Store the start node

   Node  start_node = new_node;

   Node  from_node = new_node;

   new_node = graph.addNode();

   char_map[new_node] = 'e';

   // Here we add the first edge...

   graph.addEdge( from_node, new_node );

   // ... and we add some more nodes and edges to the graph

   from_node = new_node;

   new_node = graph.addNode();

   char_map[new_node] = 'l';

   graph.addEdge( from_node, new_node );

   from_node = new_node;

   new_node = graph.addNode();

   char_map[new_node] = 'l';

   graph.addEdge( from_node, new_node );

   from_node = new_node;

   new_node = graph.addNode();

   char_map[new_node] = 'o';

   graph.addEdge( from_node, new_node );

   from_node = new_node;

   new_node = graph.addNode();

   char_map[new_node] = ' ';

   graph.addEdge( from_node, new_node );

   from_node = new_node;

   new_node = graph.addNode();

   char_map[new_node] = 'W';

   graph.addEdge( from_node, new_node );

   from_node = new_node;

   new_node = graph.addNode();

   char_map[new_node] = 'o';

   graph.addEdge( from_node, new_node );

   from_node = new_node;

   new_node = graph.addNode();

   char_map[new_node] = 'r';

   graph.addEdge( from_node, new_node );

   from_node = new_node;

   new_node = graph.addNode();

   char_map[new_node] = 'l';

   graph.addEdge( from_node, new_node );

   from_node = new_node;

   new_node = graph.addNode();

   char_map[new_node] = 'd';

   graph.addEdge( from_node, new_node );

   from_node = new_node;

   new_node = graph.addNode();

   char_map[new_node] = '\n';

   graph.addEdge( from_node, new_node );

   // iterating

   Node  current_node = start_node;

   while( current_node != INVALID )

   {

     std::cout << char_map[current_node] << std::flush;

     ListGraph::OutEdgeIt  edge(graph, current_node);

     if( edge != INVALID )

       current_node = graph.target( edge );

     else

       current_node = INVALID;

   }

   return 0;

 }