public static void Test() { Graph g1 = new Graph(4); g1.addEdge(0, 1); g1.addEdge(0, 2); g1.addEdge(1, 2); g1.addEdge(2, 0); g1.addEdge(2, 3); g1.addEdge(3, 3); DFS(g1, 2); // 2 -> 0 -> 1 -> 3 }