def partition(nums, left, right):
pivot = nums[left]
while left < right:
while left < right and nums[right]>pivot:
right -= 1
nums[left] = nums[right]
while left < right and nums[left] <= pivot:
left += 1
nums[right] = nums[left]
nums[left] = pivot
return left
def quicksort(nums, left, right):
if left > right:
return
pivot_idx = partition(nums, left, right)
quicksort(nums, left, pivot_idx+1)
quicksort(nums, pivot_idx-1, right)
