[leetcode: Python]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.
题目大意：
两个整数的汉明距离是指其二进制不相等的位的个数。

给定两个整数x和y，计算汉明距离。

注意：

0 ≤ x, y < 2^31.

解题思路：
异或运算

方法一：56ms

class Solution(object):
    def hammingDistance(self, x, y):
        """
        :type x: int
        :type y: int
        :rtype: int
        """
        x1 = bin(x)[2:]
        x2 = x1.zfill(32)
        y1 = bin(y)[2:]
        y2 = y1.zfill(32)
        h = 0
        for i in range(32):
            if x2[i] != y2[i]:
                h += 1
        return h

方法二：39ms
异或运算

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