def test_1_null_2_3_returns_3_2_1(self): btree = list(TreeNode(i) for i in range(1, 4)) btree[0].right = btree[1] btree[1].left = btree[2] self.assertEqual(Solution().postorder_traversal(btree[0]), [3, 2, 1])
def test_1_null_2_returns_2_1(self): btree = [TreeNode(1), TreeNode(2)] btree[0].right = btree[1] self.assertEqual(Solution().postorder_traversal(btree[0]), [2, 1])
def test_1_returns_1(self): self.assertEqual(Solution().postorder_traversal(TreeNode(1)), [1])