BinSort example
K=5.  list=(5,1,3,4,3,2,1,1,5,4,5)
Bins in array
key = 1
1,1,1
key = 2
2
Sorted list:
1,1,1,2,3,3,4,4,5,5,5
key = 3
3,3
key = 4
4,4
key = 5
5,5,5