Added TopologicalSort.java

src/main/java/com/rampatra/sorting/topologicalSort.java

@@ -0,0 +1,86 @@
+// A Java program to print topological sorting of a DAG 
+import java.io.*; 
+import java.util.*; 
+
+// This class represents a directed graph using adjacency 
+// list representation 
+class Graph 
+{ 
+	private int V; // No. of vertices 
+	private LinkedList<Integer> adj[]; // Adjacency List 
+
+	//Constructor 
+	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); } 
+
+	// A recursive function used by topologicalSort 
+	void topologicalSortUtil(int v, boolean visited[], 
+							Stack stack) 
+	{ 
+		// Mark the current node as visited. 
+		visited[v] = true; 
+		Integer i; 
+
+		// Recur for all the vertices adjacent to this 
+		// vertex 
+		Iterator<Integer> it = adj[v].iterator(); 
+		while (it.hasNext()) 
+		{ 
+			i = it.next(); 
+			if (!visited[i]) 
+				topologicalSortUtil(i, visited, stack); 
+		} 
+
+		// Push current vertex to stack which stores result 
+		stack.push(new Integer(v)); 
+	} 
+
+	// The function to do Topological Sort. It uses 
+	// recursive topologicalSortUtil() 
+	void topologicalSort() 
+	{ 
+		Stack stack = new Stack(); 
+
+		// Mark all the vertices as not visited 
+		boolean visited[] = new boolean[V]; 
+		for (int i = 0; i < V; i++) 
+			visited[i] = false; 
+
+		// Call the recursive helper function to store 
+		// Topological Sort starting from all vertices 
+		// one by one 
+		for (int i = 0; i < V; i++) 
+			if (visited[i] == false) 
+				topologicalSortUtil(i, visited, stack); 
+
+		// Print contents of stack 
+		while (stack.empty()==false) 
+			System.out.print(stack.pop() + " "); 
+	} 
+
+	// Driver method 
+	public static void main(String args[]) 
+	{ 
+		// Create a graph given in the above diagram 
+		Graph g = new Graph(6); 
+		g.addEdge(5, 2); 
+		g.addEdge(5, 0); 
+		g.addEdge(4, 0); 
+		g.addEdge(4, 1); 
+		g.addEdge(2, 3); 
+		g.addEdge(3, 1); 
+
+		System.out.println("Following is a Topological " + 
+						"sort of the given graph"); 
+		g.topologicalSort(); 
+	} 
+} 
+//By Sundaram Dubey