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.

位运算.

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