[7] (1)
[7, 6] (2)
[7, 6, 5] (3)
[7, 6, 5, 4] (4)
[7, 6, 5, 4, 3] (5)
[7, 6, 5, 4, 3, 2] (6)
[7, 6, 5, 4, 3, 2, 1] (7)
[7, 6, 5, 4, 3, 2, 1, 0] (8)
7 <- [6, 4, 5, 0, 3, 2, 1] (7)
6 <- [5, 4, 2, 0, 3, 1] (6)
5 <- [4, 3, 2, 0, 1] (5)
4 <- [3, 1, 2, 0] (4)
3 <- [2, 1, 0] (3)
2 <- [1, 0] (2)
1 <- [0] (1)
0 <- [] (0)
<null> <- [] (0)
<null> <- [] (0)