new_contents: # 461. Hamming Distance
  # The Hamming distance between two integers is the number of positions at which the corresponding bits are different.
  
  # Given two integers x and y, calculate the Hamming distance.
  
  # Note:
  # 0 ≤ x, y < 231.
  
  # Example:
  
  # Input: x = 1, y = 4
  
  # Output: 2
  
  # Explanation:
  # 1   (0 0 0 1)
  # 4   (0 1 0 0)
  #        ?   ?
  
  # The above arrows point to positions where the corresponding bits are different.
  
  class Solution(object):
      def hammingDistance(self, x, y):
          """
          :type x: int
          :type y: int
          :rtype: int
          """
          return bin(x ^ y).count('1')
  
  class Solution1(object):
      def hammingDistance(self, x, y):
          """
          :type x: int
          :type y: int
          :rtype: int
          """
          z = x ^ y
          count = 0
          while z:
              z &= z - 1
              count += 1
          return count
subject: add 461