二分模板

class Solution:
    def search(self, nums: List[int], target: int) -> int:
        left=0
        right=len(nums)-1

        while (left<=right):
            mid=left+right>>1
            if nums[mid]==target:
                return mid
            if nums[mid]<target:
                left=mid+1
            if nums[mid]>target:
                
                right=mid-1
        return -1