leetcode Hamming Distance 汉明距离

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.
即求二进制中不同位的个数：

class Solution {
public:
    int hammingDistance(int x, int y) {
        int z = x^y;
        int ans = 0;
        while (z) {
            if (z & 1) 
                ans++;
            z >>= 1;
        }
        return ans;
    }
};

1、直接异或
2、求二进制中1的个数