how to get height of a BFS tree

[kilyx]

This is my code that implements a directed graph.It prints the nodes in bfs order
but how can i get then the height of the corresponding tree?
thanks

  static void BFS(Vector<Vector<Integer>> g,int s){
		Queue<Integer> q = new LinkedList<Integer>();
		boolean[] visited=new boolean[g.size()];
		for(int i=0;i<g.size();i++){
			visited[i]=false;
		}
		    q.offer(s);
		    System.out.print(s);
			while(q.isEmpty()==false){
				int u=q.remove();
				if (visited[u]==false){
					visited[u]=true;
					for ( int x=0;x<g.get(u).size();x++){
						int v =g.get(u).get(x);
						q.offer(v);
						if(visited[v]==false) {
							System.out.print(" "+v);
							}
					}
				}
			}
			
 	}

[kilyx]

so i'm wondering if given and adjacency list of a directed graph and its bfs array wich gives me the bfs order of its nodes i can retrieve the height of the bfs tree