diff -r 7cc2418766c3 -r ed4c8506e151 demo/hello_lemon.cc
--- a/demo/hello_lemon.cc	Sat Nov 01 08:25:30 2008 +0000
+++ b/demo/hello_lemon.cc	Mon Nov 03 23:46:30 2008 +0100
@@ -17,12 +17,9 @@
  */
 
 ///\file
-///\brief Demonstrating the basic concepts and fetures of LEMON
+///\brief Simple "Hello World!" program for LEMON.
 ///
-/// This program is intended to be a "Hello World!" program that shows
-/// the very basic notions of LEMON: \ref graphs "graphs" and
-/// \ref maps "maps".
-///
+/// Simple "Hello World!" program for LEMON.
 /// \include hello_lemon.cc
 
 #include <iostream>
@@ -30,67 +27,17 @@
 
 int main()
 {
-  // Convenience type definitions
-  typedef lemon::ListDigraph Digraph;
-  typedef Digraph::Node Node;
-  typedef Digraph::Arc Arc;
-  typedef Digraph::NodeIt NodeIt;
-  typedef Digraph::ArcIt ArcIt;
-  typedef Digraph::ArcMap<int> LengthMap;
-  using lemon::INVALID;
+  typedef lemon::ListDigraph Graph;
+  Graph g;
 
-  // Create a directed graph
-  Digraph g;
+  Graph::Node u = g.addNode();
+  Graph::Node v = g.addNode();
+  Graph::Arc  e = g.addArc(u, v);
 
-  // Add nodes to the digraph
-  Node v1 = g.addNode();
-  Node v2 = g.addNode();
-  Node v3 = g.addNode();
-  Node v4 = g.addNode();
-
-  // Add arcs to the digraph
-  Arc v1_v2 = g.addArc(v1, v2);
-  Arc v1_v3 = g.addArc(v1, v3);
-  Arc v2_v3 = g.addArc(v2, v3);
-  Arc v2_v4 = g.addArc(v2, v4);
-  Arc v3_v4 = g.addArc(v3, v4);
-
-  // Create an arc map (length)
-  LengthMap length(g);
-
-  // Set the length of each arc
-  length[v1_v2]  = 10;
-  length[v1_v3]  = 20;
-  length[v2_v3] = 5;
-  length[v2_v4] = 25;
-  length[v3_v4] = 10;
-
-  // Welcome message
-  std::cout << "Hello World!" << std::endl;
-  std::cout << "This is LEMON library here. We have a direceted graph.";
-  std::cout << std::endl << std::endl;
-
-  // Iterate through the nodes and print their IDs
-  std::cout << "Nodes:";
-  for (NodeIt n(g); n != INVALID; ++n)
-    std::cout << " " << g.id(n);
-  std::cout << std::endl;
-
-  // Iterate through the arcs and print the IDs of their
-  // source and target nodes
-  std::cout << "Arcs:";
-  for (ArcIt a(g); a != INVALID; ++a)
-    std::cout << " (" << g.id(g.source(a)) << ","
-              << g.id(g.target(a)) << ")";
-  std::cout << std::endl << std::endl;
-
-  // Iterate through the arcs and print their length
-  std::cout << "There is a map on the arcs (length):" << std::endl;
-  std::cout << std::endl;
-  for (ArcIt a(g); a != INVALID; ++a)
-    std::cout << "length(" << g.id(g.source(a)) << ","
-              << g.id(g.target(a)) << ")=" << length[a] << std::endl;
-  std::cout << std::endl;
+  std::cout << "Hello World! This is LEMON library here." << std::endl;
+  std::cout << "We have a directed graph with "
+            << countNodes(g) << " nodes and "
+            << countArcs(g) << " arc." << std::endl;
 
   return 0;
 }