/**
* Adds the directed edge <tt>e</tt> to the edge-weighted digraph.
*
* @param e the edge
* @throws java.lang.IndexOutOfBoundsException unless endpoints of edge are between 0 and V-1
*/
public void addEdge(DirectedEdge e) {
int v = e.from();
int w = e.to();
validateVertex(v);
validateVertex(w);
adj[v].add(e);
E++;
}
/**
* Returns the number of directed edges incident from vertex <tt>v</tt>. This is known as the
* <em>outdegree</em> of vertex <tt>v</tt>.
*
* @return the outdegree of vertex <tt>v</tt>
* @param v the vertex
* @throws java.lang.IndexOutOfBoundsException unless 0 <= v < V
*/
public int outdegree(int v) {
validateVertex(v);
return adj[v].size();
}
/**
* Returns the directed edges incident from vertex <tt>v</tt>.
*
* @return the directed edges incident from vertex <tt>v</tt> as an Iterable
* @param v the vertex
* @throws java.lang.IndexOutOfBoundsException unless 0 <= v < V
*/
public Iterable<DirectedEdge> adj(int v) {
validateVertex(v);
return adj[v];
}