Approach 1. Bit operations and Count 1 numbers

Intuition:

Hamming Distance is the number of 1 in the XOR of A and B.

```
class Solution(object):
def hammingDistance(self, x, y):
"""
:type x: int
:type y: int
:rtype: int
"""
tmp = x ^ y
# 求tmp中1的个数
count = 0
while tmp != 0:
count += 1
tmp = tmp & tmp-1
return count
```