def quickSort(alist): quickSortHelper(alist, 0, len(alist)-1) def quickSortHelper(alist, first, last): if first < last: splitPoint = partition(alist, first, last) quickSortHelper(alist, first, splitPoint-1) quickSortHelper(alist, splitPoint+1, last) def partition(alist, first, last): pivotvlue = alist[first] leftmark = first+1 rightmark = last done = False while not done: while alist[leftmark] <= pivotvlue and leftmark <= rightmark: leftmark += 1 while alist[rightmark] >= pivotvlue and rightmark >= leftmark: rightmark -= 1 if leftmark > rightmark: done = True else: alist[leftmark], alist[rightmark] = alist[rightmark], alist[leftmark] alist[rightmark], alist[first] = alist[first], alist[rightmark] return rightmark alist = [54,26,93,17,77,31,44,55,20] alist2 = [1] quickSort(alist2) print(alist2)