[LeetCode]Number of 1 Bits

题目描述:

Write a function that takes an unsigned integer and returns the number of ’1' bits it has (also known as the Hamming weight).

For example, the 32-bit integer ’11' has binary representation 00000000000000000000000000001011, so the function should return 3.

解题思路:

注意是无符号整形。

class Solution {
public:
    int hammingWeight(uint32_t n) {
        int count = 0;
        while (true) {
            if (n == 0) break;
            if (n == 1) {
                ++count;
                break;
            }
            
            if (n & 1 != 0) {
                ++count;
            }
            n >>= 1;
        }
        
        return count;
    }
};