/**
* Adds the undirected edge v-w to this graph.
*
* @param v one vertex in the edge
* @param w the other vertex in the edge
* @throws IndexOutOfBoundsException unless both 0 <= v < V and 0 <= w < V
*/
public void addEdge(int v, int w) {
validateVertex(v);
validateVertex(w);
E++;
adj[v].add(w);
adj[w].add(v);
}
/**
* Returns the degree of vertex <tt>v</tt>.
*
* @param v the vertex
* @return the degree of vertex <tt>v</tt>
* @throws IndexOutOfBoundsException unless 0 <= v < V
*/
public int degree(int v) {
validateVertex(v);
return adj[v].size();
}
/**
* Returns the vertices adjacent to vertex <tt>v</tt>.
*
* @param v the vertex
* @return the vertices adjacent to vertex <tt>v</tt>, as an iterable
* @throws IndexOutOfBoundsException unless 0 <= v < V
*/
public Iterable<Integer> adj(int v) {
validateVertex(v);
return adj[v];
}
