Oct 12, 2019
diff --git a/src/main/java/com/rampatra/sorting/topologicalSort.java b/src/main/java/com/rampatra/sorting/topologicalSort.java
 // 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
Original file line number	Diff line number	Diff line change
		@@ -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