import java.util.InputMismatchException; import java.util.Scanner; import java.util.Stack; public class UndirectedConnectivityDfs { private Stack stack; public UndirectedConnectivityDfs() { stack = new Stack(); } public void dfs(int adjacency_matrix[][], int source) { int number_of_nodes = adjacency_matrix[source].length - 1; int visited[] = new int[number_of_nodes + 1]; int element = source; int i = source; visited[source] = 1; stack.push(source); while (!stack.isEmpty()) { element = stack.peek(); i = element; while (i <= number_of_nodes) { if (adjacency_matrix[element][i] == 1 && visited[i] == 0) { stack.push(i); visited[i] = 1; element = i; i = 1; continue; } i++; } stack.pop(); } boolean connected = false; for (int vertex = 1; vertex <= number_of_nodes; vertex++) { if (visited[vertex] == 1) { connected = true; } else { connected = false; break; } } if (connected) { System.out.println("The graph is connected"); } else { System.out.println("The graph is disconnected"); } } public static void main(String...arg) { int number_of_nodes, source; Scanner scanner = null; try { System.out.println("Enter the number of nodes in the graph"); scanner = new Scanner(System.in); number_of_nodes = scanner.nextInt(); int adjacency_matrix[][] = new int[number_of_nodes + 1][number_of_nodes + 1]; System.out.println("Enter the adjacency matrix"); for (int i = 1; i <= number_of_nodes; i++) for (int j = 1; j <= number_of_nodes; j++) adjacency_matrix[i][j] = scanner.nextInt(); for (int i = 1; i <= number_of_nodes; i++) { for (int j = 1; j <= number_of_nodes; j++) { if (adjacency_matrix[i][j] == 1 && adjacency_matrix[j][i] == 0) { adjacency_matrix[j][i] = 1; } } } System.out.println("Enter the source for the graph"); source = scanner.nextInt(); UndirectedConnectivityDfs undirectedConnectivity= new UndirectedConnectivityDfs(); undirectedConnectivity.dfs(adjacency_matrix, source); } catch(InputMismatchException inputMismatch) { System.out.println("Wrong Input format"); } scanner.close(); } } /* Enter the number of nodes in the graph 5 Enter the adjacency matrix 0 1 0 1 0 0 0 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 Enter the source for the graph 1 The graph is disconnected