C++ Please

There are cases where we need to switch a representation of a graph to the other representation. Add methods to the Graph classes that convert an AdjListGraph to an AdjMatrixGraph (or vice versa). In AdjListGraph, the conversion function would have the signature AdjMatrixGraph &convert() which would convert the graph stored in adjacency list format to adjacency matrix format and return a reference to the newly created graph. In AdjMatrixGraph, the conversion function would have the signature AdjListGraph &convert() and convert that AdjMatrixGraph and return a reference to the newly created AdjListGraph.