[0, 1, 0, 0, 0]
[0, 1, 2, 0, 0]
[3, 1, 2, 0, 0]
[3, 1, 2, 4, 0]
[5, 1, 2, 4, 3]
[5, 1, 2, 4, 3]
5 1 2 4 3