LeetCode 278 - 第一个错误的版本

class Solution:
    def firstBadVersion(self, n: int) -> int:
        left, right = 0, n
        while left <= right:
            mid = (left + right) // 2
            result = isBadVersion(mid)
            if result:
                right = mid - 1
            else:
                left = mid + 1
        return left