快速排序quick_sort（python的两种实现方式）

排序算法有很多，目前最好的是quick_sort:unstable，spatial complexity is nlogN.

快速排序原理

python实现

严蔚敏的 datastruct书中有伪代码实现，因为Amazon面试需要排序，所以用python实现了。
两种实现方法，功能一致，效率没测，请高手留言

第一种实现

标准算法，严蔚敏书中的伪代码实现

#!/usr/bin/python
# -*- coding: utf-8 -*-
'''
@author: willard
'''

def quick_sort_standord(array,low,high):
    ''' realize from book "data struct" of author 严蔚敏
    '''
    if low < high:
        key_index = partion(array,low,high)
        quick_sort_standord(array,low,key_index)
        quick_sort_standord(array,key_index+1,high)

def partion(array,low,high):
    key = array[low]
    while low < high:
        while low < high and array[high] >= key:
            high -= 1
        if low < high:
            array[low] = array[high]

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

    array[low] = key
    return low

if __name__ == '__main__':
    array2 = [9,3,2,1,4,6,7,0,5]

    print array2
    quick_sort_standord(array2,0,len(array2)-1)
    print array2

第二种实现

这是特殊实现，

#!/usr/bin/python
# -*- coding: utf-8 -*-
'''
@author: willard
'''

def sub_sort(array,low,high):
    key = array[low]
    while low < high:
        while low < high and array[high] >= key:
            high -= 1
        while low < high and array[high] < key:
            array[low] = array[high]
            low += 1
            array[high] = array[low]
    array[low] = key
    return low


def quick_sort1(array,low,high):
    if low < high:
        key_index = sub_sort(array,low,high)
        quick_sort1(array,low,key_index)
        quick_sort1(array,key_index+1,high)

if __name__ == '__main__':
    #array = [8,10,9,6,4,16,5,13,26,18,2,45,34,23,1,7,3]
    array1 = [7,3,5,6,2,4,1]

    print array1
    quick_sort1(array1,0,len(array1)-1)
    print array1