二分法查找算法
如果有这样一个列表，让你从这个列表中找到66的位置，你要怎么办？
l = [2,3,5,10,15,16,18,22,26,30,32,35,41,42,43,55,56,66,67,69,72,76,82,83,88]
实现
l = [2,3,5,10,15,16,18,22,26,30,32,35,41,42,43,55,56,66,67,69,72,76,82,83,88,89]
l.sort()
def func(l,aim):
if len(l) == 0:
print("not find")
return
index = (len(l)-1)//2
if aim > l[index]:
func(l[index+1:],aim)
elif aim < l[index]:
func(l[:index-1],aim)
elif aim == l[index]:
print('find ', aim)
else:
print("not find")
func(l,31)
not find
l = [2,3,5,10,15,16,18,22,26,30,32,35,41,42,43,55,56,66,67,69,72,76,82,83,88,89]
l.sort()
def search(num,l,start=None,end=None):
start = start if start else 0
end = end if end else len(l) - 1
mid = (end - start)//2 + start
if start > end:
return None
elif l[mid] > num :
return search(num,l,start,mid-1)
elif l[mid] < num:
return search(num,l,mid+1,end)
elif l[mid] == num:
return mid
print(search(31,l))
None