bubble sort would have only 3 compare ops, and 6 assignments at worst case (it will be very similar if not identical to the behavior of insertion sort in this case):
if (a > b)
swap(a,b)
if (b > c)
swap(b,c)
if (a > b)
swap(a,b)
print a,b,c
It cannot be done in less then 3 compares because there are n!=6
possible permutations for the array, and ceil(log_2(n!)) = 3