import java.io.*;

import java.util.*;

class GraphBFS {

private int V;

private LinkedList<Integer> adj[];

GraphBFS(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) {

boolean visited[] = new boolean[V];

LinkedList<Integer> queue = new LinkedList<Integer>();

visited[s]=true;

queue.add(s);

while (queue.size() != 0) {

s = queue.poll();

System.out.print(s+" ");

Iterator<Integer> i = adj[s].listIterator();

while (i.hasNext()) {

int n = i.next();

if (!visited[n]) {

visited[n] = true;

queue.add(n);

}

}

}

}

public static void main(String args[]) {

GraphBFS g = new GraphBFS(4);

g.addEdge(0, 1);

g.addEdge(0, 2);

g.addEdge(1, 2);

g.addEdge(2, 0);

g.addEdge(2, 3);

g.addEdge(3, 3);

System.out.println("Following is Breadth First Traversal "+

"(starting from vertex 2)");

g.BFS(2);

}

}