Added the algorithm for Depth First Search of a Graph

graph_dfs.cpp

@@ -0,0 +1,75 @@
+// C++ program to print DFS traversal for a given given graph 
+#include<iostream> 
+#include		 <list> 
+using namespace std; 
+
+class Graph 
+{ 
+	int V; // No. of vertices 
+	list<int> *adj; // Pointer to an array containing adjacency lists 
+	void DFSUtil(int v, bool visited[]); // A function used by DFS 
+public: 
+	Graph(int V); // Constructor 
+	void addEdge(int v, int w); // function to add an edge to graph 
+	void DFS(); // prints DFS traversal of the complete graph 
+}; 
+
+Graph::Graph(int V) 
+{ 
+	this->V = V; 
+	adj = new list<int>[V]; 
+} 
+
+void Graph::addEdge(int v, int w) 
+{ 
+	adj[v].push_back(w); // Add w to v’s list. 
+} 
+
+void Graph::DFSUtil(int v, bool visited[]) 
+{ 
+	// Mark the current node as visited and print it 
+	visited[v] = true; 
+	cout << v << " "; 
+
+	// Recur for all the vertices adjacent to this vertex 
+	list<int>::iterator i; 
+	for(i = adj[v].begin(); i != adj[v].end(); ++i) 
+		if(!visited[*i]) 
+			DFSUtil(*i, visited); 
+} 
+
+// The function to do DFS traversal. It uses recursive DFSUtil() 
+void Graph::DFS() 
+{ 
+	// Mark all the vertices as not visited 
+	bool *visited = new bool[V]; 
+	for (int i = 0; i < V; i++) 
+		visited[i] = false; 
+
+	// Call the recursive helper function to print DFS traversal 
+	// starting from all vertices one by one 
+	for (int i = 0; i < V; i++) 
+		if (visited[i] == false) 
+			DFSUtil(i, visited); 
+} 
+
+int main() 
+{ 
+	// Create a graph given in the above diagram 
+	int n,e,u,v;
+	cout<<"Enter the number of vertices"<<endl;
+	cin>>n;
+	Graph g(n); 
+	cout<<"Enter the number of edges, with indexing starting from 0"<<endl;
+	cin>>e;
+	for(int i=0;i<e;i++){
+		cin>>u>>v;
+		g.addEdge(u,v); 
+
+	}
+	cout << "Following is Depth First Traversaln"; 
+	g.DFS(); 
+
+	return 0; 
+} 
+