public void LevelOrderBottomTest_Null()
        {
            var solution = new _107_BinaryTreeLevelOrderTraversal2();
            var result   = solution.LevelOrderBottom(null);

            AssertHelper.AssertList(new List <IList <int> >(), result);
        }
        public void LevelOrderBottomTest()
        {
            var solution = new _107_BinaryTreeLevelOrderTraversal2();
            var result   = solution.LevelOrderBottom(TestHelper.GenerateTree(new int?[] { 3, 9, 20, null, null, 15, 7 }));

            AssertHelper.AssertList(new List <IList <int> >()
            {
                new List <int>()
                {
                    15, 7
                },
                new List <int>()
                {
                    9, 20
                },
                new List <int>()
                {
                    3
                },
            }, result);
        }