In typical algorithms and applications related to graphs and networks,

 In typical algorithms and applications related to graphs and networks,

 we usually encounter situations in which a specific alteration of a graph

 we usually encounter situations in which a specific alteration of a graph

 has to be considered.

 has to be considered.

 If some nodes or arcs have to be hidden (maybe temporarily) or the reverse

 If some nodes or arcs have to be hidden (maybe temporarily) or the reverse

 oriented graph has to be used, then this is the case.

 oriented graph has to be used, then this is the case.

 making a copy of the graph structure along with the required maps

 making a copy of the graph structure along with the required maps

 could be rather expensive (in time or in memory usage) compared to the

 could be rather expensive (in time or in memory usage) compared to the

 operations that should be performed on the altered graph.

 operations that should be performed on the altered graph.

 In such cases, the LEMON \e graph \e adaptor \e classes could be used.

 In such cases, the LEMON \e graph \e adaptor \e classes could be used.

 This technique yields convenient tools that help writing compact and elegant

 This technique yields convenient tools that help writing compact and elegant

 code, and makes it possible to easily implement complex algorithms based on

 code, and makes it possible to easily implement complex algorithms based on

 well tested standard components.

 well tested standard components.

 \code

 \code

   ListDigraph g;

   ListDigraph g;

   ReverseDigraph<ListDigraph> rg(g);

   ReverseDigraph<ListDigraph> rg(g);

   int result = algorithm(rg);

   int result = algorithm(rg);