Pseudocode §
lo: lower bound index of (sub)list, inclusivehi: upper bound index of (sub)list, inclusive
quicksort(items, lo, hi):
if lo >= hi:
return items
pivot_index = partition(items, lo, hi)
quicksort(items, lo, pivot_index - 1)
quicksort(items, pivot_index + 1, hi)
partition(items, lo, hi):
pivot_index = hi
pivot = items[pivot_index]
j = -1
for i in lo until hi:
if items[i] <= pivot:
j += 1
swap items[i] with items[j]
new_pivot_index = j + 1
swap items[new_pivot_index] with items[pivot_index]
return new_pivot_index