python编程---example12

快速排序算法。 

def quick_sort(arr,start=0,end=None):
	if end is None:
		end = len(arr) - 1
	if end <= start:
		return(arr)
	i,j = start,end
	ref = arr[start]
	while j>i:
		if arr[j]>=ref:
			j = j - 1
		else:
			arr[i],arr[j],arr[i+1] = arr[j],arr[i+1],arr[i]
			i = i + 1
	quick_sort(arr,start=start,end=i-1)
	quick_sort(arr,start=i+1,end=end)
	return(arr)

print(quick_sort([2,4,1,6,3,1,9,5,8,3,0,1,7]))