python 快速排序

版本1：

http://blog.csdn.net/qq_14959801/article/details/53055485

版本2：

https://www.cnblogs.com/Jesse8/p/8110627.html

 1 array = [ 9,1,22,9,31,-5,45,3,6,2,11 ]
 2 def quick_sort(array,left,right):
 3     if array == "":
 4         return ""
 5     low = left
 6     high = right
 7     key = array[low]
 8 
 9     if left < right:
10         while low < high:
11             while low<high and key <= array[high]:
12                 high -= 1
13             array[low] = array[high]
14 
15             while low<high and key >= array[low]:
16                 low += 1
17             array[high] = array[low]
18 
19             array[low] = key