python实现简单二分查找
#!/usr/bin/python
def binary_search(list, item):
low = 0
high = len(list)-1
while low <= high:
mid = (low + high)/2
print(mid)
guess = list[mid]
if guess == item:
return mid
elif guess > item:
high = mid - 1
else:
low = mid+1
return None
mylist = [1,3,5,7,9]
print binary_search(mylist,3)
print binary_search(mylist,-1)