/* -*- mode: C++; indent-tabs-mode: nil; -*-

  *

  * 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.

  *

  */

 namespace lemon {

 /**

 [PAGE]hello_lemon[PAGE] Compile Your First Code

 First of all you have to install LEMON on your system (see

 \ref install for instructions).

 After that you can paste the following code segment into a file

 <tt>hello_lemon.cc</tt> to have a first working program that uses LEMON.

 \dontinclude hello_lemon.cc

 \skip #include

 \until }

 In this small example a directed graph is created with two nodes and

 an arc added to it.

 Now let us compile this code.

 (We suppose that you have it in a file called <tt>hello_lemon.cc</tt>.)

 If LEMON is installed <b>system-wide</b> (into directory \c /usr/local),

 then it is very easy to compile this program with the

 following command (the argument <tt>-lemon</tt> tells the compiler

 that we are using the installed LEMON).

 \verbatim

 g++ -lemon hello_lemon.cc -o hello_lemon

 \endverbatim

 As a result you will get the exacutable \c hello_lemon in the current

 directory, which you can run by the following command.

 \verbatim

 ./hello_lemon

 \endverbatim

 If LEMON is installed <b>user-local</b> into a directory

 (e.g. <tt>~/lemon</tt>) or if you just skipped the step

 <tt>make install</tt>, then compiling the code is a bit more difficult.

 You have to issue a command like this.

 \verbatim

 g++ -lemon -I ~/lemon -L ~/lemon/lemon/.libs hello_lemon.cc -o hello_lemon

 \endverbatim

 If everything has gone well, then our program prints out the followings.

 \verbatim

 Hello World! This is LEMON library here.

 We have a directed graph with 2 nodes and 1 arc.

 \endverbatim

 If you managed to compile and run this example code without any problems,

 you may go on reading this tutorial to get to know the basic notions,

 features and tools of LEMON. However if you encountered problems that

 you did not manage to solve, do not hesitate to

 <a href="mailto:lemon-user@lemon.cs.elte.hu"><b>contact us</b></a>.

 [TRAILER]

 */

 }