I've implemented the digraph data structure using adjacency matrix. The main code only creates a digraph and shows the user three options: insert an arc; delete an arc; and show the digraph.
I often use the digraph like a graph.
I will insert some algorithms related to this code in the future.
The main source for my project until here can be found on the below link (but the explanation is in portuguese)
http://www.ime.usp.br/~pf/algoritmos_para_grafos/aulas/digraphdatastructs.html