Returns a random simple digraph on V vertices, E edges and (at least) c strong components. The vertices are randomly assigned integer labels between 0 and c-1 (corresponding to strong components). Then, a strong component is creates among the vertices with the same label. Next, random edges (either between two vertices with the same labels or from a vetex with a smaller label to a vertex with a larger label). The number of components will be equal to the number of distinct labels that are assigned to vertices.

public static Digraph Strong(
	int V,
	int E,
	int c
)