algo/python/15_bsearch/bsearch_recursion.py
2019-03-05 11:47:35 +08:00

23 lines
531 B
Python

"""
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)