> For the complete documentation index, see [llms.txt](https://garylai.gitbook.io/algorithm-and-data-structure/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://garylai.gitbook.io/algorithm-and-data-structure/problems/binary-search/guess-number-higher-or-lower.md).

# 374. Guess Number Higher or Lower

[374. Guess Number Higher or Lower](https://leetcode.com/problems/guess-number-higher-or-lower/)

```python
# 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:
        left = 1
        right = n
        while left <= right:
            mid = left + (right - left) // 2
            if guess(mid) == 1:
                left = mid + 1
            elif guess(mid) == -1:
                right = mid - 1
            else:
                return mid
```