def test_k_more_than_nodes(self): self.assertEqual(kth_smallest(self.root, 6), -1)
def test_fifth_smallest_value(self): # largest value self.assertEqual(kth_smallest(self.root, 5), 20)
def test_fourth_smallest_value(self): # second largest value self.assertEqual(kth_smallest(self.root, 4), 18)
def test_third_smallest_value(self): self.assertEqual(kth_smallest(self.root, 3), 17)
def test_second_smallest_value(self): self.assertEqual(kth_smallest(self.root, 2), 15)
def test_smallest_value(self): self.assertEqual(kth_smallest(self.root, 1), 9)