/**

 @defgroup datas Data Structures

 This group describes the several graph structures implemented in LEMON.

 */

 /**

 @defgroup graphs Graph Structures

 @ingroup datas

 \brief Graph structures implemented in LEMON.

 The implementation of combinatorial algorithms heavily relies on 

 efficient graph implementations. LEMON offers data structures which are 

 planned to be easily used in an experimental phase of implementation studies, 

 and thereafter the program code can be made efficient by small modifications. 

 The most efficient implementation of diverse applications require the

 usage of different physical graph implementations. These differences

 appear in the size of graph we require to handle, memory or time usage

 limitations or in the set of operations through which the graph can be

 accessed.  LEMON provides several physical graph structures to meet

 the diverging requirements of the possible users.  In order to save on

 running time or on memory usage, some structures may fail to provide

 some graph features like edge or node deletion.

 Alteration of standard containers need a very limited number of 

 operations, these together satisfy the everyday requirements. 

 In the case of graph structures, different operations are needed which do 

 not alter the physical graph, but gives another view. If some nodes or 

 edges have to be hidden or the reverse oriented graph have to be used, then 

 this is the case. It also may happen that in a flow implementation 

 the residual graph can be accessed by another algorithm, or a node-set 

 is to be shrunk for another algorithm. 

 LEMON also provides a variety of graphs for these requirements called 

 \ref graph_adaptors "graph adaptors". Adaptors cannot be used alone but only 

 in conjunction with other graph representation. 

 You are free to use the graph structure that fit your requirements

 the best, most graph algorithms and auxiliary data structures can be used

 with any graph structures. 

 */

 /**

 @defgroup semi_adaptors Semi-Adaptors Classes for Graphs

 @ingroup graphs

 \brief Graph types between real graphs and graph adaptors.

 Graph types between real graphs and graph adaptors. These classes wrap

 graphs to give new functionality as the adaptors do it. On the other

 hand they are not light-weight structures as the adaptors.

 */

 /**

 @defgroup maps Maps 

 @ingroup datas

 \brief Some special purpose map to make life easier.

 LEMON provides several special maps that e.g. combine

 new maps from existing ones.

 */

 /**

 @defgroup graph_maps Graph Maps 

 @ingroup maps

 \brief Special Graph-Related Maps.

 These maps are specifically designed to assign values to the nodes and edges of

 graphs.

 */

 /**

 \defgroup map_adaptors Map Adaptors

 \ingroup maps

 \brief Tools to create new maps from existing ones

 Map adaptors are used to create "implicit" maps from other maps.

 Most of them are \ref lemon::concept::ReadMap "ReadMap"s. They can

 make arithmetic operations between one or two maps (negation, scaling,

 addition, multiplication etc.) or e.g. convert a map to another one

 of different Value type.

 */

 /**

 @defgroup matrices Matrices 

 @ingroup datas

 \brief Two dimensional data storages.

 Two dimensional data storages.

 */

 /**

 @defgroup paths Path Structures

 @ingroup datas

 \brief Path structures implemented in LEMON.

 LEMON provides flexible data structures

 to work with paths.

 All of them have the same interface, especially they can be built or extended

 using a standard Builder subclass. This make is easy to have e.g. the Dijkstra

 algorithm to store its result in any kind of path structure.

 \sa lemon::concept::Path

 */

 /**

 @defgroup auxdat Auxiliary Data Structures

 @ingroup datas

 \brief Some data structures implemented in LEMON.

 This group describes the data structures implemented in LEMON in

 order to make it easier to implement combinatorial algorithms.

 */

 /**

 @defgroup graphbits Tools to Make It Easier to Make Graphs

 @ingroup auxdat

 \brief Tools to Make It Easier to Make Graphs.

 This group describes the tools that makes it easier to make graphs and

 the maps that dynamically update with the graph changes.

 */

 /**

 @defgroup algs Algorithms

 \brief This group describes the several algorithms

 implemented in LEMON.

 This group describes the several algorithms

 implemented in LEMON.

 */

 /**

 @defgroup gutils General Graph Utilities

 @ingroup algs

 \brief This group describes some simple general graph utilities.

 This group describes some simple general graph utilities.

 */

 /**

 @defgroup flowalgs Path and Flow Algorithms

 @ingroup algs

 \brief This group describes the algorithms

 for finding paths and flows in graphs.

 This group describes the algorithms

 for finding paths and flows in graphs.

 \image html flow.png

 \image latex flow.eps "Graph flow" width=\textwidth

 */

 /**

 @defgroup topology Topology related algorithms

 @ingroup algs

 \brief This group describes the algorithms

 for discover the topology of the graphs.

 This group describes the algorithms

 for discover the topology of the graphs.

 \image html edge_biconnected_components.png

 \image latex edge_biconnected_components.eps "bi-edge-connected components" width=\textwidth

 */

 /**

 @defgroup matching Matching algorithms in graphs and bipartite graphs

 @ingroup algs

 \brief This group describes the algorithms

 for find matchings in graphs and bipartite graphs.

 This group provides some algorithm objects and function

 to calculate matchings in graphs and bipartite graphs.

 \image html bipartite_matching.png

 \image latex bipartite_matching.eps "Bipartite Matching" width=\textwidth

 */

 /**

 @defgroup spantree Minimum Cost Spanning Tree Algorithms

 @ingroup algs

 \brief This group contains the algorithms for finding a minimum cost spanning

 tree in a graph

 This group contains the algorithms for finding a minimum cost spanning

 tree in a graph

 */

 /**

 @defgroup auxalg Auxiliary Algorithms

 @ingroup algs

 \brief Some algorithms implemented in LEMON.

 This group describes the algorithms in LEMON in order to make 

 it easier to implement complex algorithms.

 */

 /**

 @defgroup gen_opt_group General Optimization Tools

 \brief This group describes some general optimization frameworks

 implemented in LEMON.

 This group describes some general optimization frameworks

 implemented in LEMON.

 */

 /**

 @defgroup misc Miscellaneous Tools

 Here you can find several useful tools for development,

 debugging and testing.

 */

 /**

 @defgroup timecount Time measuring and Counting

 @ingroup misc

 Here you can find simple tools for measuring the performance

 of algorithms.

 */

 /**

 @defgroup io_group Input-Output

 \brief Several Graph Input-Output methods

 Here you can find tools for importing and exporting graphs 

 and graph related data. Now it supports the LEMON format, the

 \c DIMACS format and the encapsulated postscript format.

 */

 /**

 @defgroup lemon_io Lemon Input-Output

 @ingroup io_group

 \brief Reading and writing LEMON format

 Methods for reading and writing LEMON format. More about this

 format you can find on the \ref graph-io-page "Graph Input-Output"

 tutorial pages.

 */

 /**

 @defgroup section_io Section readers and writers

 @ingroup lemon_io

 \brief Section readers and writers for lemon Input-Output.

 Here you can find which section readers and writers can attach to

 the LemonReader and LemonWriter.

 */

 /**

 @defgroup item_io Item Readers and Writers

 @ingroup lemon_io

 \brief Item readers and writers for lemon Input-Output.

 The Input-Output classes can handle more data type by example

 as map or attribute value. Each of these should be written and

 read some way. The module make possible to do this.  

 */

 /**

 @defgroup eps_io Postscript exporting

 @ingroup io_group

 \brief General \c EPS drawer and graph exporter

 This group contains general \c EPS drawing methods and special

 graph exporting tools. 

 */

 /**

 @defgroup exceptions Exceptions

 This group contains the exceptions thrown by LEMON library

 */

 /**

 @defgroup concept Concepts

 \brief Skeleton classes and concept checking classes

 This group describes the data/algorithm skeletons and concept checking

 classes implemented in LEMON.

 The purpose of the classes in this group is fourfold.

 - These classes contain the documentations of the concepts. In order

   to avoid document multiplications, an implementation of a concept

   simply refers to the corresponding concept class.

 - These classes declare every functions, <tt>typedef<tt>s etc. an

   implementation of the concepts should provide, however completely

   without implementations and real data structures behind the

   interface. On the other hand they should provide nothing else. All

   the algorithms working on a data structure meeting a certain concept

   should compile with these classes. (Though it will not run properly,

   of course.) In this way it is easily to check if an algorithm

   doesn't use any extra feature of a certain implementation.

 - The concept descriptor classes also provide a <em>checker class<em>

   that makes it possible check whether a certain implementation of a

   concept indeed provides all the required features.

 - Finally, They can serve as a skeleton of a new implementation of a concept.

 */

 /**

 @defgroup graph_concepts Graph Structure Concepts

 @ingroup concept

 \brief Skeleton and concept checking classes for graph structures

 This group contains the skeletons and concept checking classes of LEMON's

 graph structures and helper classes used to implement these.

 */

 /* --- Unused group

 @defgroup experimental Experimental Structures and Algorithms

 This group contains some Experimental structures and algorithms.

 The stuff here is subject to change.

 */

 /**

 \anchor demoprograms

 @defgroup demos Demo programs

 Some demo programs are listed here. Their full source codes can be found in

 the \c demo subdirectory of the source tree.

 The standard compilation procedure (<tt>./configure;make</tt>) will compile

 them, as well. 

 */