Create dfs.java

this is a dfs algorithm, specially meant for beginners. PrajaktaSathe#2

javaAlgo/dfs.java

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+import java.util.LinkedList;
+
+public class GraphDFS {
+    private LinkedList<Integer>[] adjLists;
+    private boolean[] visited;
+
+    // Graph Constructor
+    GraphDFS(int vertices) {
+        adjLists = new LinkedList[vertices];
+        visited = new boolean[vertices];
+
+        for (int i = 0; i < vertices; i++) {
+            adjLists[i] = new LinkedList<>();
+        }
+    }
+
+    // Add an edge to the graph
+    void addEdge(int src, int dest) {
+        adjLists[src].add(dest);
+    }
+
+    // DFS traversal of the vertices reachable from v
+    void DFS(int vertex) {
+        visited[vertex] = true;
+        System.out.print(vertex + " ");
+
+        for (int adj : adjLists[vertex]) {
+            if (!visited[adj]) {
+                DFS(adj);
+            }
+        }
+    }
+
+    public static void main(String[] args) {
+        GraphDFS graph = new GraphDFS(4);
+
+        graph.addEdge(0, 1);
+        graph.addEdge(0, 2);
+        graph.addEdge(1, 2);
+        graph.addEdge(2, 0);
+        graph.addEdge(2, 3);
+        graph.addEdge(3, 3);
+
+        System.out.println("Depth First Search starting from vertex 2:");
+        graph.DFS(2);
+    }
+}