Quicksort example

.py

def partition(list, l, r):
	pivot = list[r]
	i=l
	j=r-1
	
	while True:
		while i<r and list[i]<=pivot:
			i+=1
		while j>l and list[j]>pivot:
			j-=1
		if i<j:
			list[i], list[j] = list[j], list[i]
		else:
			break
	list[r], list[i] = list[i], list[r]
	return i

def quicksort(list, l, r):
	if l>=r:
		return
	pivot_index = partition(list, l, r)
	quicksort(list, l, pivot_index-1)
	quicksort(list, pivot_index+1, r)

A = [1, 3, 5, 7, 9, 8, 6, 4, 2]
quicksort(A, 0, len(A)-1)
print(str(A))