#!/usr/bin/env python
def qsort3(alist, lower, upper):
print(alist)
if lower >= upper:
return
pivot = alist[lower]
left, right = lower + 1, upper
while left <= right:
while left <= right and alist[left] < pivot:
left += 1
while left <= right and alist[right] >= pivot:
right -= 1
if left > right:
break
# swap while left <= right
alist[left], alist[right] = alist[right], alist[left]
# swap the smaller with pivot
alist[lower], alist[right] = alist[right], alist[lower]
qsort3(alist, lower, right - 1)
qsort3(alist, right + 1, upper)
unsortedArray = [8,7,6,5,4,3,2,1]
print(qsort3(unsortedArray, 0, len(unsortedArray) - 1))
