// BFS algorithm in Java
import java.util.*;
public class Graph {
private int V;
private LinkedList adj[];
// Create a graph
Graph(int v) {
V = v;
adj = new LinkedList[v];
for (int i = 0; i < v; ++i)
adj[i] = new LinkedList();
}
// Add edges to the graph
void addEdge(int v, int w) {
adj[v].add(w);
}
// BFS algorithm
void BFS(int s) {
boolean visited[] = new boolean[V];
LinkedList queue = new LinkedList();
visited[s] = true;
queue.add(s);
while (queue.size() != 0) {
s = queue.poll();
System.out.print(s + " ");
Iterator 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[]) {
Graph g = new Graph(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);
}
}