/**

 \page getstart How to start using LEMON

 In this page we detail how to start using LEMON, from downloading it to 

 your computer, through the steps of installation to showing a simple

 "Hello World" type program that already uses LEMON. If anything is not 

 clear write to our FAQ.

 \todo Is this FAQ thing a good idea here? Is there such a thing? If

 twice YES then a link comes here.

 \section downloadLEMON How to download LEMON

 You can download LEMON from the following web site:

 \section installLEMON How to install LEMON

 In order to install LEMON you have to do the following

 Ide kell írni:

 -Hol fordul (Windows-os fordító nem fordítja, unix/linux alatt gcc hanyas verziója kell)

 -

 \section helloworld My first program using LEMON

 If you have installed LEMON on your system you can paste the following code

 segment into a file to have a first working program that uses library LEMON.

 \code

 #include <iostream>

 #include <lemon/list_graph.h>

 using namespace lemon;

 int main()

 {

   typedef ListGraph Graph;

   typedef Graph::Edge Edge;

   typedef Graph::InEdgeIt InEdgeIt;

   typedef Graph::OutEdgeIt OutEdgeIt;

   typedef Graph::EdgeIt EdgeIt;

   typedef Graph::Node Node;

   typedef Graph::NodeIt NodeIt;

   Graph g;

   for (int i = 0; i < 3; i++)

     g.addNode();

   for (NodeIt i(g); i!=INVALID; ++i)

     for (NodeIt j(g); j!=INVALID; ++j)

       if (i != j) g.addEdge(i, j);

   std::cout << "Nodes:";

   for (NodeIt i(g); i!=INVALID; ++i)

     std::cout << " " << g.id(i);

   std::cout << std::endl;

   std::cout << "Edges:";

   for (EdgeIt i(g); i!=INVALID; ++i)

     std::cout << " (" << g.id(g.source(i)) << "," << g.id(g.target(i)) << ")";

   std::cout << std::endl;

 \endcode

 ListGraph is one of LEMON's graph classes. It is based on linked lists,

 therefore iterating throuh its edges and nodes is fast.

 After some convenient typedefs we create a graph and add three nodes to it.

 Then we add edges to it to form a complete graph.

 Then we iterate through all nodes of the graph. We use a constructor of the

 node iterator to initialize it to the first node. The operator++ is used to

 step to the next node. Using operator++ on the iterator pointing to the last

 node invalidates the iterator i.e. sets its value to

 \ref lemon::INVALID "INVALID". This is what we exploit in the stop condition.

 We can also iterate through all edges of the graph very similarly. The 

 \c target and

 \c source member functions can be used to access the endpoints of an edge.

 The previous code fragment prints out the following:

 \code

 Nodes: 2 1 0

 Edges: (0,2) (1,2) (0,1) (2,1) (1,0) (2,0)

 \endcode

 If you want to see more features, go to the \ref quicktour "Quick Tour to

 LEMON", if you want to see see some demo programs then go to our 

 \ref demoprograms "Demo Programs" page! 

 */