athos@1169: /**
athos@1169: 
alpar@1170: \page quicktour Quick Tour to LEMON
alpar@1170: 
athos@1175: Let us first answer the question <b>"What do I want to use LEMON for?"
athos@1175: </b>. 
athos@1175: LEMON is a C++ library, so you can use it if you want to write C++ 
athos@1175: programs. What kind of tasks does the library LEMON help to solve? 
athos@1175: It helps to write programs that solve optimization problems that arise
athos@1175: frequently when <b>designing and testing certain networks</b>, for example
athos@1175: in telecommunication, computer networks, and other areas that I cannot
athos@1175: think of now. A very natural way of modelling these networks is by means
athos@1175: of a <b> graph</b> (we will always mean a directed graph by that). 
athos@1175: So if you want to write a program that works with 
athos@1175: graphs then you might find it useful to use our library LEMON.
athos@1175: 
athos@1175: 
athos@1175: 
athos@1175: Some examples are the following:
athos@1175: 
athos@1175: - First we give two examples that show how to instantiate a graph. The
athos@1175: first one shows the methods that add nodes and edges, but one will
athos@1175: usually use the second way which reads a graph from a stream (file).
athos@1175: 
athos@1175: 
athos@1175: -# The following code fragment shows how to fill a graph with data.
athos@1175: 
athos@1175:  \code
athos@1175: 
athos@1175:   typedef ListGraph Graph;
athos@1175:   typedef Graph::Edge Edge;
athos@1175:   typedef Graph::InEdgeIt InEdgeIt;
athos@1175:   typedef Graph::OutEdgeIt OutEdgeIt;
athos@1175:   typedef Graph::EdgeIt EdgeIt;
athos@1175:   typedef Graph::Node Node;
athos@1175:   typedef Graph::NodeIt NodeIt;
athos@1175: 
athos@1175:   Graph g;
athos@1175:   
athos@1175:   for (int i = 0; i < 3; i++)
athos@1175:     g.addNode();
athos@1175:   
athos@1175:   for (NodeIt i(g); i!=INVALID; ++i)
athos@1175:     for (NodeIt j(g); j!=INVALID; ++j)
athos@1175:       if (i != j) g.addEdge(i, j);
athos@1175: 
athos@1175:  \endcode 
athos@1175: 
athos@1175:  -#
athos@1175: 
athos@1175: - If you want to solve some transportation problems in a network then 
athos@1175: you will want to find shortest paths between nodes of a graph. This is 
athos@1175: usually solved using Dijkstra's algorithm. A utility
athos@1175: that solves this is  the \ref lemon::Dijkstra "LEMON Dijkstra class".
athos@1175: A simple program using the \ref lemon::Dijkstra "LEMON Dijkstra class" is
athos@1175: as follows (we assume that the graph is already given in the memory):
athos@1175: 
athos@1175: \code
athos@1175: 
athos@1175: \endcode
athos@1175: 
athos@1175: - If you want to design a network and want to minimize the total length
athos@1175: of wires then you might be looking for a <b>minimum spanning tree</b> in
athos@1175: an undirected graph. This can be found using the Kruskal algorithm: the 
athos@1175: class \ref lemon::Kruskal "LEMON Kruskal class" does this job for you.
athos@1175: The following code fragment shows an example:
athos@1175: 
athos@1175: \code
athos@1175: 
athos@1175: \endcode
athos@1175: 
athos@1175: 
athos@1175: 
athos@1175: Some more detailed introduction can be obtained by following the links 
athos@1175: below:
athos@1175: 
athos@1169: \ref graphs "Graph structures"
athos@1175: play a central role in LEMON, so if you are new to the library,
athos@1169: you probably should start \ref graphs "here".
athos@1175: (You can also find that page along with others under
athos@1175: <a class="el" href="pages.html"> Related Pages </a>.)
athos@1169: 
athos@1169: If you are 
athos@1169: interested in data structures and algorithms in more details, then
athos@1169: you should browse the reference manual part of the documentation.
athos@1169: Section <a class="el" href="modules.html"> Modules </a>
athos@1169:  is a good starting point for this.
athos@1175: */