#!coding:utf8

def quicksort(list_num, left, right):

    if left > right:

        return

    low = left

    high = right

    privot= list_num[left]

    while low<high:

        while low < high and list_num[high] > privot:

            high-=1

        if low < high:

            list_num[low] = list_num[high]

        while low < high and list_num[low] <= privot:

            low+=1

        if low < high:

             list_num[high] = list_num[low]

    list_num[low] = privot

    quicksort(list_num, left, low-1)

    quicksort(list_num, low+1, right)

if __name__ == "__main__":

    test = [7,2,1,6,5,4,4,2]

    quicksort(test,0, len(test)-1)