Added graph dfs

Graph/dfs.java

@@ -0,0 +1,57 @@
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+public class Graph {
+    private Map<Integer, List<Integer>> adjList;
+
+    // Constructor to initialize the graph
+    public Graph() {
+        adjList = new HashMap<>();
+    }
+
+    // Method to add an edge between two nodes (directed graph)
+    public void addEdge(int source, int destination) {
+        adjList.putIfAbsent(source, new ArrayList<>());
+        adjList.get(source).add(destination);
+    }
+
+    // DFS utility function
+    private void dfsUtil(int vertex, boolean[] visited) {
+        visited[vertex] = true;
+        System.out.print(vertex + " "); // Print the vertex as part of DFS traversal
+
+        // Visit all neighbors of the current vertex
+        List<Integer> neighbors = adjList.get(vertex);
+        if (neighbors != null) {
+            for (int neighbor : neighbors) {
+                if (!visited[neighbor]) {
+                    dfsUtil(neighbor, visited);
+                }
+            }
+        }
+    }
+
+    // DFS traversal function
+    public void dfs(int startVertex) {
+        boolean[] visited = new boolean[adjList.size()];
+        System.out.println("DFS Traversal starting from vertex " + startVertex + ":");
+        dfsUtil(startVertex, visited);
+    }
+
+    public static void main(String[] args) {
+        Graph graph = new Graph();
+
+        // Add edges to the graph
+        graph.addEdge(0, 1);
+        graph.addEdge(0, 2);
+        graph.addEdge(1, 2);
+        graph.addEdge(2, 0);
+        graph.addEdge(2, 3);
+        graph.addEdge(3, 3);
+
+        // Perform DFS starting from vertex 2
+        graph.dfs(2);
+    }
+}