Code:
import java.util.Scanner;
import java.util.Stack;
public class Connectivity_DFS
{
private final int vertices;
private int[][] adjacency_matrix;
private Stack
public Connectivity_DFS(int v)
{
vertices = v;
adjacency_matrix = new int[vertices + 1][vertices + 1];
stack = new Stack
}
public void makeEdge(int to, int from, int edge)
{
try
{
adjacency_matrix[to][from] = edge;
adjacency_matrix[from][to] = edge;
} catch (ArrayIndexOutOfBoundsException index)
{
System.out.println("The vertices does not exists");
}
}
public int getEdge(int to, int from)
{
try
{
return adjacency_matrix[to][from];
} catch (ArrayIndexOutOfBoundsException index)
{
System.out.println("The vertices does not exists");
}
return -1;
}
public void dfs(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;
stack.push(source);
while (!stack.isEmpty())
{
element = stack.pop();
i = 1;// element;
while (i <= number_of_nodes)
{
if (adjacency_matrix[element][i] == 1 && visited[i] == 0)
{
stack.push(i);
visited[i] = 1;
}
i++;
}
}
System.out.print("The source node " + source + " is connected to: ");
int count = 0;
for (int v = 1; v <= number_of_nodes; v++)
if (visited[v] == 1)
{
System.out.print(v + " ");
count++;
}
if (count == number_of_nodes)
System.out.print("\nThe Graph is Connected ");
else
System.out.print("\nThe Graph is Disconnected ");
}
public static void main(String args[])
{
int v, e, count = 1, to = 0, from = 0;
Scanner sc = new Scanner(System.in);
Connectivity_DFS graph;
System.out.println("The Undirected Graph Connectivity Test");
try
{
System.out.println("Enter the number of vertices: ");
v = sc.nextInt();
System.out.println("Enter the number of edges: ");
e = sc.nextInt();
graph = new Connectivity_DFS(v);
System.out.println("Enter the edges:
while (count <= e)
{
to = sc.nextInt();
from = sc.nextInt();
graph.makeEdge(to, from, 1);
count++;
}
System.out.println("The adjacency matrix for the given graph is: ");
System.out.print(" ");
for (int i = 1; i <= v; i++)
System.out.print(i + " ");
System.out.println();
for (int i = 1; i <= v; i++)
{
System.out.print(i + " ");
for (int j = 1; j <= v; j++)
System.out.print(graph.getEdge(i, j) + " ");
System.out.println();
}
System.out.println("Enter the Source Node: ");
int sourceNode = sc.nextInt();
graph.dfs(sourceNode);
} catch (Exception E)
{
System.out.println("Somthing went wrong");
}
sc.close();
}
}
Output:
The Undirected Graph Connectivity Test(DFS)
Enter the number of vertices:
4
Enter the number of edges:
2
Enter the edges:
1 2
1 3
The adjacency matrix for the given graph is:
1 2 3 4
1 0 1 1 0
2 1 0 0 0
3 1 0 0 0
4 0 0 0 0
Enter the Source Node:
2
The source node 2 is connected to: 1 2 3
The Graph is Disconnected
The Undirected Graph Connectivity Test(DFS)
Enter the number of vertices:
4
Enter the number of edges:
4
Enter the edges:
1 2
1 3
1 4
2 4
The adjacency matrix for the given graph is:
1 2 3 4
1 0 1 1 1
2 1 0 0 1
3 1 0 0 0
4 1 1 0 0
Enter the Source Node:
4
The source node 4 is connected to: 1 2 3 4
The Graph is Connected
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