Problem can be found in here!
# The isBadVersion API is defined as followed
def isBadVersion(version: int) -> bool:
...
class Solution:
def firstBadVersion(self, n: int) -> int:
left, right = 1, n
while left < right:
mid = (left+right) // 2
if isBadVersion(mid):
right = mid
else:
left = mid + 1
return left