new_contents: """
  Find the nth digit of the infinite integer sequence 1, 2, 3, 4, 5, 6, 7, 8, 9,
  10, 11, ...
  
  Note:
      n is positive and will fit within the range of a 32-bit signed integer 
      (n < 2 ** 31).
  
  Example 1:
  
      Input:
      3
      
      Output:
      3
  
  Example 2:
  
      Input:
      11
      
      Output:
      0
  
  Explanation:
      The 11th digit of the sequence 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, ... is a
      0, which is part of the number 10.
  """
  class Solution(object):
      def findNthDigit(self, n):
          """
          :type n: int
          :rtype: int
          """
          if n <= 0:
              return 0
          elif n <= 9:
              return n
          i = 1
          while n - self.totalDigits(i) >= 0:
              n -= self.totalDigits(i)
              i += 1
          curr = 10 ** (i - 1) + ((n - 1) // i)
          n -= (n // i) * i
          return int(str(curr)[n - 1])
  
      def totalDigits(self, n):
          return (10 ** n - 10 ** (n - 1)) * n
  
  a = Solution()
  print(a.findNthDigit(10) == 1)
  print(a.findNthDigit(190) == 1)
  
subject: add 400