12. Hamming Distance

Title：

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.

Example 1:

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.

Note:

 0 ≤ x, y < 2³¹. 

Analysis of Title：

The example is clearly. To sum up, Hamming Distance is the different of x and y in binary.

Test case：

1
4

Python：

class Solution(object):
　　def hammingDistance(self, x, y):
　　"""
　　:type x: int
　　:type y: int
　　:rtype: int
　　"""
　　return bin(x^y).count("1")

Analysis of Code：

1. x^y　　Although '^' is a binary operationx, python well auto change int into binary, and then back-change to int, so x^y=1^4=001^100=101=5

2.bin(5) is str