Exploring graphs

Graph.java

import java.util.*;

class Graph {

    int V; //num. of Vertices
    LinkedList<Integer> adj[]; //Adjacency lists

    Graph(int v) {
        V = v;
        adj = new LinkedList[v];
        for (int i = 0 ; i<v; i++) {
            adj[i] = new LinkedList<>();
        }
    }

    void addEdge(int v, int w) {
        adj[v].add(w);
    }

    void BFS(int s) {

        //Mark all vertices as unvisited (by default elements in array are false)
        boolean visited[] = new boolean[V];

        //Queue creating
        LinkedList<Integer> queue = new LinkedList<>();

        //marked current vertex as visited
        visited[s] = true;
        //enqueue this vertex
        queue.add(s);

        while (queue.size() != 0) {
            System.out.println("\n\nBefore dequeue: " + Arrays.toString(queue.toArray()));
            //dequeue vertex
            s = queue.poll();
            System.out.println("Getting from queue: " + s);

            // Get all adjacent vertices of the dequeued vertex s
            // If a adjacent has not been visited, then mark it
            // visited and enqueue it
            Iterator<Integer> i = adj[s].listIterator();
            while(i.hasNext()) {
                int n = i.next();
                if (!visited[n]) {
                    System.out.println("Visited: " + s + " -> " + n);
                    visited[n] = true;
                    queue.add(n);
                }
            }
        }

    }

    public static void main(String[] args) {
        Graph graph = new Graph(10);

        graph.addEdge(0,1);
        graph.addEdge(0,2);
        graph.addEdge(0,3);
        graph.addEdge(1,4);
        graph.addEdge(2,5);
        graph.addEdge(2,6);
        graph.addEdge(3,7);
        graph.addEdge(4,8);
        graph.addEdge(5,9);

        System.out.println("Starting BFS from vertex 0");
        graph.BFS(0);
    }
}