For the spanning tree traversals, the following files
need to be included in the compilation:

   GrafTrav.cpp   The main to exercise the traversals
   Graph.cpp      The class CGraph
   GrUtil.cpp     Utility classes for CGraph

For the all-paths algorithms, the following files
need to be included in the compilation:

   ExpoMain.cpp   The main to exercise the algorithms
   Graph.cpp      The class CGraph
   GraphAll.cpp   The derived class CGraphAll
   GrUtil.cpp     Utility classes for CGraph
