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

array = [ 9,1,22,9,31,-5,45,3,6,2,11 ]
def quick_sort(array,left,right):
    if array == "":
        return ""
    low = left
    high = right
    key = array[low]

    if left < right:
        while low < high:
            while low<high and key <= array[high]:
                high -= 1
            array[low] = array[high]

            while low<high and key >= array[low]:
                low += 1
            array[high] = array[low]

            array[low] = key