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