461. Hamming Distance

題目原文

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 < 2^31.

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.

解題思路

1. 利用exclusive-or特性，相同的為0，不同的為1。

2. 然後檢查有幾個不同的bit數。

程式解答

class Solution 
{
public:
    int hammingDistance(int x, int y) 
    {   
        int counter = 0;
        int x_xor_y = x ^ y;
        
        for (int i = 0; i < 32; i++)
        {
            if (x_xor_y % 2)
                counter++;
            x_xor_y >>= 1;
        }
        return counter;
    }
};