1import java.util.ArrayList;
2import java.util.LinkedList;
3import java.util.Queue;
4 
5public class GraphBFS {
6 
7    public static void bfs(ArrayList<ArrayList<Integer>> graph, int start) {
8 
9        boolean[] visited = new boolean[graph.size()];
10        Queue<Integer> queue = new LinkedList<>();
11 
12        visited[start] = true;
13        queue.offer(start);
14 
15        while (!queue.isEmpty()) {
16 
17            int node = queue.poll();
18 
19            System.out.print(node + " ");
20 
21            for (int neighbor : graph.get(node)) {
22 
23                if (!visited[neighbor]) {
24 
25                    visited[neighbor] = true;
26                    queue.offer(neighbor);
27                }
28            }
29        }
30    }
31 
32    public static void main(String[] args) {
33 
34        int vertices = 6;
35 
36        ArrayList<ArrayList<Integer>> graph = new ArrayList<>();
37 
38        for (int i = 0; i < vertices; i++) {
39            graph.add(new ArrayList<>());
40        }
41 
42        graph.get(0).add(1);
43        graph.get(0).add(2);
44 
45        graph.get(1).add(3);
46        graph.get(1).add(4);
47 
48        graph.get(2).add(5);
49 
50        System.out.println("BFS Traversal:");
51 
52        bfs(graph, 0);
53    }
54}