Added Topological Sort Algorithm for Graph

Author: sachin10fi

TopologicalSortGraph.java

@@ -0,0 +1,60 @@
+import java.util.*;
+
+class DirectedGraph {
+    private int numberOfVertices;
+    private List<List<Integer>> adjacencyList;
+
+    public DirectedGraph(int vertices) {
+        numberOfVertices = vertices;
+        adjacencyList = new ArrayList<>(numberOfVertices);
+        for (int i = 0; i < numberOfVertices; i++) {
+            adjacencyList.add(new ArrayList<>());
+        }
+    }
+
+    public void addEdge(int source, int destination) {
+        adjacencyList.get(source).add(destination);
+    }
+
+    private void performTopologicalSortUtil(int vertex, boolean[] visited, Stack<Integer> stack) {
+        visited[vertex] = true;
+        for (Integer neighbor : adjacencyList.get(vertex)) {
+            if (!visited[neighbor]) {
+                performTopologicalSortUtil(neighbor, visited, stack);
+            }
+        }
+        stack.push(vertex);
+    }
+
+    public void performTopologicalSort() {
+        Stack<Integer> topologicalOrderStack = new Stack<>();
+        boolean[] visited = new boolean[numberOfVertices];
+
+        Arrays.fill(visited, false);
+
+        for (int vertex = 0; vertex < numberOfVertices; vertex++) {
+            if (!visited[vertex]) {
+                performTopologicalSortUtil(vertex, visited, topologicalOrderStack);
+            }
+        }
+
+        // Print the topological order
+        System.out.println("Topological Sort Order:");
+        while (!topologicalOrderStack.isEmpty()) {
+            System.out.print(topologicalOrderStack.pop() + " ");
+        }
+    }
+
+    public static void main(String[] args) {
+        DirectedGraph graph = new DirectedGraph(6);
+        graph.addEdge(5, 2);
+        graph.addEdge(5, 0);
+        graph.addEdge(4, 0);
+        graph.addEdge(4, 1);
+        graph.addEdge(2, 3);
+        graph.addEdge(3, 1);
+
+        System.out.println("Performing Topological Sort:");
+        graph.performTopologicalSort();
+    }
+}