二分查找
算法入门第一题 二分查找
思路:在一个升序的list中,用中间数(mid)来进行匹配,如果target比中间数大,说明target在list右边,left=mid+1,如果target比中间数小,说明target在list左边,right=mid-1
from typing import List class Solution: def search(self, nums: List[int], target: int) -> int: # write code here if len(nums) == 0: return -1 left = 0 right = len(nums) - 1 while left <= right: mid = int((left + right) / 2) if nums[mid] < target: left = mid + 1 elif nums[mid] > target: right = mid - 1 else: return mid # elif nums[mid] == target: # return mid return -1 list1 = [9] s = Solution() print(s.search(list1, 2))