【leetcode】Number of 1 Bits

題目描述：

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.

解題思路：

簡單的除就能夠了。

class Solution:
    # @param n, an integer
    # @return an integer
    def hammingWeight(self, n):
        res = 0
        while n != 0:
            if n % 2 != 0:
                res += 1
            n /=2
        return res