solutions/0278-First-Bad-Version/0278.py

# The isBadVersion API is already defined for you.
# @param version, an integer
# @return a bool
# def isBadVersion(version):

class Solution(object):
    def firstBadVersion(self, n):
        """
        :type n: int
        :rtype: int
        """
        low, high = 1, n  # 1-n
        while low <= high:
            mid = int((low + high) / 2)
            if isBadVersion(mid) == False:
                low = mid + 1
            else:
                high = mid - 1
        return low