Day 1 - First Bad Version

Solution.py

# https://leetcode.com/explore/challenge/card/may-leetcoding-challenge/534/week-1-may-1st-may-7th/3316/

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

class Solution:
    def firstBadVersion(self, n):
        return self.bs(1, n)
    
    def bs(self, a, b):
        if a > b:
            return b if isBadVersion(b) else a
        
        m = int((a + b) / 2)
        
        if isBadVersion(m):
            return self.bs(a, m - 1) 
        else:
            return self.bs(m + 1, b)