来自胡春生的问题
[][]2[]-------------------[][]9[]18[]--------------[]05[][][]-------------0
[][]
2[]-------------------
[][]9[]
18[]
--------------
[]05
[][][]
-------------


[][]2[]-------------------[][]9[]18[]--------------[]05[][][]-------------0
[][]
2[]-------------------
[][]9[]
18[]
--------------
[]05
[][][]
-------------
(9)(5)
--------------
2(1))(1)(9)9(5)
18(9)
--------------
(1)05
(1)(0)(5)
--------------