简介二分查找算法与相关的Python实现示例

>>> def find(self, num):
 l = len(self)
 first = 0
 end = l - 1
 mid = 0
 if l == 0:
 self.insert(0,num)
 return False
 while first < end:
 mid = (first + end)/2
 if num > self[mid]:
 first = mid + 1
 elif num < self[mid]:
 end = mid - 1
 else:
 break
 if first == end:
 if self[first] > num:
 self.insert(first, num)
 return False
 elif self[first] < num:
 self.insert(first + 1, num)
 return False
 else:
 return True
 elif first > end:
 self.insert(first, num)
 return False
 else:
 return True

>>> list_d = ['a','b','c','d','e','f','d','t']
>>> value_d = 't'
>>> aa=find(list_d,value_d)
>>> aa
True
>>> value_d='ha'
>>> aa=find(list_d,value_d)
>>> aa
False