def quick_sort(left, right, array):
if left < right and (right - left + 1) > 10:
split_point = qsort.partition(array, left, right)
array = quick_sort(left, split_point - 1, array)
array = quick_sort(split_point + 1, right, array)
elif left < right:
array[left:right + 1] = insertion_sort(array[left:right + 1])
return array
def order(A, p, r, i):
'''Return the i-th smallest element of A[p:r+1].'''
if p == r:
return A[p]
q = partition(A, p, r)
k = q - p + 1
if i <= k:
return order(A, p, q, i)
else:
return order(A, q + 1, r, i - k)
def ksel(x, left, right, k):
if right == left and k == 0:
return x[left]
if right == left + 1:
if k == 0:
return min(x[left], x[right])
elif k == 1:
return max(x[left], x[right])
p_idx = left + (right - left) / 2
p_idx_new = partition(x, left, right, p_idx)
if k == p_idx_new - left + 1:
return x[p_idx_new]
elif k < p_idx_new - left + 1:
return ksel(x, left, p_idx_new - 1, k)
else:
return ksel(x, p_idx_new + 1, right, k - p_idx_new)
