[binary search - simple] 374 Guess the size of the number

【 subject 】
【 Example 】
Example 1：

Input ：n = 10, pick = 6
Output ：6

Example 2：

Input ：n = 1, pick = 1
Output ：1

Example 3：

Input ：n = 2, pick = 1
Output ：1

Example 4：

Input ：n = 2, pick = 2
Output ：2

【 Tips 】

1 <= n <= 231 - 1
1 <= pick <= n

【 Code 】
Execution time ：28 ms, In all Python3 Defeated in submission 96.22% Users of
Memory consumption ：14.8 MB, In all Python3 Defeated in submission 74.59% Users of
Pass the test case ：25 / 25

# The guess API is already defined for you.
# @param num, your guess
# @return -1 if my number is lower, 1 if my number is higher, otherwise return 0
# def guess(num: int) -> int:

class Solution:
    def guessNumber(self, n: int) -> int:
        low,high=1,n
        while low<=high:
            mid=low+(high-low)//2
            if guess(mid)==0:
                return mid
            elif guess(mid)>0:
                low=mid+1
            else:
                high=mid-1
        return -1