二分查找递归实现 Python

This commit is contained in:
dreamkong 2019-03-05 11:47:35 +08:00
parent 615fbab083
commit f90eb8f710

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@ -0,0 +1,22 @@
"""
Author: dreamkong
"""
from typing import List
def bsearch(nums: List[int], target: int) -> int:
return bsearch_internally(nums, 0, len(nums)-1, target)
def bsearch_internally(nums: List[int], low: int, high: int, target: int) -> int:
if low > high:
return -1
mid = low+int((high-low) >> 2)
if nums[mid] == target:
return mid
elif nums[mid] < target:
return bsearch_internally(nums, mid+1, high, target)
else:
return bsearch_internally(nums, low, mid-1, target)