Depth First Search or DFS for a Graph

[Hanzala421]

// Java program to print DFS
//mtraversal from a given given
// graph
import java.io.;
import java.util.;

// This class represents a
// directed graph using adjacency
// list representation
class Graph {
private int V; // No. of vertices

// Array of lists for
// Adjacency List Representation
private LinkedList<Integer> adj[];

// Constructor
@SuppressWarnings("unchecked") Graph(int v)
{
	V = v;
	adj = new LinkedList[v];
	for (int i = 0; i < v; ++i)
		adj[i] = new LinkedList();
}

// Function to add an edge into the graph
void addEdge(int v, int w)
{
	adj[v].add(w); // Add w to v's list.
}

// A function used by DFS
void DFSUtil(int v, boolean visited[])
{
	// Mark the current node as visited and print it
	visited[v] = true;
	System.out.print(v + " ");

	// Recur for all the vertices adjacent to this
	// vertex
	Iterator<Integer> i = adj[v].listIterator();
	while (i.hasNext())
	{
		int n = i.next();
		if (!visited[n])
			DFSUtil(n, visited);
	}
}

// The function to do DFS traversal.
// It uses recursive
// DFSUtil()
void DFS(int v)
{
	// Mark all the vertices as
	// not visited(set as
	// false by default in java)
	boolean visited[] = new boolean[V];

	// Call the recursive helper
	// function to print DFS
	// traversal
	DFSUtil(v, visited);
}

// Driver Code
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 Depth First Traversal "
		+ "(starting from vertex 2)");

	g.DFS(2);
}

}
// This code is contributed by Aakash Hasija

[Hanzala421]

saw useful,so added..