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..