# Write a function that takes an unsigned integer and returns the number of ’1' bits
# it has (also known as the Hamming weight).
#
# For example, the 32-bit integer ’11' has binary representation 00000000000000000000000000001011,
# so the function should return 3.

# author li.hzh
class Solution(object):
    def hammingWeight(self, n):
        """
        :type n: int
        :rtype: int
        """
        result = 0
        while n:
            n = n & n - 1
            result += 1
        return  result

print(Solution().hammingWeight(11))