content: import java.util.InputMismatchException;
  import java.util.LinkedList;
  import java.util.Queue;
  import java.util.Scanner;
  
  public class BFS {
  
      private Queue<Integer> queue;
  
      public BFS() {
          queue = new LinkedList<Integer>();
      }
  
      public void bfs(int adjacency_matrix[][], int source) {
          int number_of_nodes = adjacency_matrix[source].length - 1;
  
          int[] visited = new int[number_of_nodes + 1];
          int i, element;
  
          visited[source] = 1;
          queue.add(source);
  
          while (!queue.isEmpty()) {
              element = queue.remove();
              i = element;
              System.out.print(i + "\t");
              while (i <= number_of_nodes) {
                  if (adjacency_matrix[element][i] == 1 && visited[i] == 0) {
                      queue.add(i);
                      visited[i] = 1;
                  }
                  i++;
              }
          }
      }
  
      public static void main(String... arg) {
          int number_no_nodes, source;
          Scanner scanner = null;
  
          try {
              System.out.println("Enter the number of nodes in the graph");
              scanner = new Scanner(System.in);
              number_no_nodes = scanner.nextInt();
  
              int adjacency_matrix[][] = new int[number_no_nodes + 1][number_no_nodes + 1];
              System.out.println("Enter the adjacency matrix");
              for (int i = 1; i <= number_no_nodes; i++)
                  for (int j = 1; j <= number_no_nodes; j++)
                      adjacency_matrix[i][j] = scanner.nextInt();
  
              System.out.println("Enter the source for the graph");
              source = scanner.nextInt();
  
              System.out.println("The BFS traversal of the graph is ");
              BFS bfs = new BFS();
              bfs.bfs(adjacency_matrix, source);
  
          } catch (InputMismatchException inputMismatch) {
              System.out.println("Wrong Input Format");
          }
          scanner.close();
      }
  }
  