Python 排序 快速排序

# -*- coding: utf-8 -*-
# author: zhonghua
# filename: sort_quick.py
# create: 2016/3/28
# version: 1.0

# 快速排序

def quick(lst, left, right):
    if left >= right:
        return

    key = lst[left]
    low = left
    high = right
    # 大循环
    while low < high:
        # 必须是lst[high] >= key, 否则left和right会停在一个位置重复循环
        while low < high and lst[high] >= key:
            high -= 1
        lst[low] = lst[high]
        # 这里不能是lst[low] <= key, 否则会出现low超出lst范围的情况
        while low < high and lst[low] < key:
            low += 1
        lst[high] = lst[low]
    lst[low] = key
    # 递归
    quick(lst, left, low)
    quick(lst, low + 1, right)

if __name__ ==  '__main__':
    lst = [19, 28, 30, 5, 8, 60, 72, 94, 68, 28]
    quick(lst, 0, len(lst)-1)
    for i in lst:
        print i