python算法实践4 快速排序
#快速排序
def Partition(mylist, low, high):
tmp = mylist[low]
while low < high:
while low < high and mylist[high] >= tmp:
high = high - 1
if low < high:
mylist[low] = mylist[high]
low = low + 1
while low < high and mylist[low] <= tmp:
low = low + 1
if low < high:
mylist[high] = mylist[low]
high = high - 1
mylist[low] = tmp
return low
def QuickSort(mylist, low, high):
if low < high:
pivotpos = Partition(mylist, low, high)
QuickSort(mylist, low, pivotpos - 1)
QuickSort(mylist, pivotpos + 1, high)
mylist0 = [11, 10, 3, 12, 33, 1000, 1, 333, -11]
QuickSort(mylist0, 0, len(mylist0) - 1)
print(mylist0)
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最近,想在我的YouMoney(http://code.google.com/p/youmoney/)里面增加提取用户操作系统版本信息。比如windows用户,可能要返回Windows XP ,或者Windows 2003, 苹果用户应该返回Mac OS X 10.5.8。用了很多办法,包括在mac系统里调用系统命令,取环境变量,等等。最后无意发现,原来python里里面有个pl ......
实验环境:windows xp + vim
文件:test.py。编码:ansi
我们的目标操作test.py中保存的非英文字母。
文件头的#encoding=utf8/gbk,这个是用来说明源文件的硬盘编码以便python识别[4]。
----------------------------------------------
输入:
x = '中文'
输出: 编译失败
编译时需要知道‘中文’的硬盘编 ......
And last here is the overload operators example:
# map() takes two (or more) arguments, a function and a list to apply the function to
# lambda can be put anywhere a function is expected
# map() calls lambada for every element in the self list
# since Vector has overloaded __getitem__ and __len_ ......
python字典排序
1、
准备知识:
在python里,字典dictionary是内置的数据类型,是个无序的存储结构,每一元素是key-value对:
如:dict = {‘username’:‘password’,‘database’:‘master’},其中‘username’和& ......
#冒泡排序
def BubbleSort(mylist):
n = len(mylist)
i = 0
j = 0
bExchange = False
for i in range(1, n):
bExchange = False
j = n - 1
while j >= i:
if mylist[j] < mylist[j - 1]:
tmp = mylist[j]
myli ......