new_contents: #!/usr/bin/env python
  # encoding: utf-8
  
  """
  first-bad-version.py
   
  Created by Shuailong on 2016-03-16.
  
  https://leetcode.com/problems/first-bad-version/.
  
  """
  
  # The isBadVersion API is already defined for you.
  # @param version, an integer
  # @return a bool
  
  def isBadVersion(version):
      return version >= 10
  
  class Solution(object):
  
      def firstBadVersion(self, n):
          """
          :type n: int
          :rtype: int
          """
          l = 1
          r = n
          while l <= r:
              m = (l+r)/2
              if isBadVersion(m) and not isBadVersion(m-1):
                  return m
              elif isBadVersion(m) and isBadVersion(m-1):
                  r = m-1
              elif not isBadVersion(m) and not isBadVersion(m-1):
                  l = m+1
  
          
  
  def main():
      solution = Solution()
      n = 1000
      print solution.firstBadVersion(n)
      
  if __name__ == '__main__':
      main()
  
          
subject: solve 1 problem