start        [5,2,4,6,1,3]
j=2 key=2 shifts=1 insert at 1  [2,5,4,6,1,3]
j=3 key=4 shifts=1 insert at 2  [2,4,5,6,1,3]
j=4 key=6 shifts=0 insert at 4  [2,4,5,6,1,3]
j=5 key=1 shifts=4 insert at 1  [1,2,4,5,6,3]
j=6 key=3 shifts=3 insert at 3  [1,2,3,4,5,6]
