python 二分查找和快速排序实例详解_Python

python 二分查找和快速排序实例详解

2020-12-11 00:32Inc_Cool Python

本文通过实例代码给大家详细介绍了python 二分查找和快速排序,的相关知识，需要的朋友可以参考下

思想简单，细节颇多；本以为很简单的两个小程序，写起来发现bug频出，留此纪念。

									#usr/bin/env python

									def binary_search(lst,t):

									  low=0

									  height=len(lst)-1

									  quicksort(lst,0,height)

									  print lst

									  while low<=height: 

									    mid = (low+height)/2

									    if lst[mid] == t:

									      return lst[mid]

									    elif lst[mid]>t:

									      height=mid-1

									    else:

									      low=mid+1

									  return -1

									def quicksort( lst, left , right):

									  low=left

									  high=right

									  key=lst[left]

									  if left>=right:

									    return 0

									  while low<high:

									    while low<high and key<lst[high]:

									      high=high-1

									    lst[low]=lst[high]

									    while low<high and key>lst[low]:

									      print lst[low]

									      low=low+1

									    lst[high]=lst[low]

									    lst[low]=key

									  quicksort( lst , left ,low-1)

									  quicksort( lst , low+1 , right)

									if __name__=='__main__':

									  print binary_search([4,8,1,5,10,2,12,3,6,9],4)