[LeetCode] Number of 1 Bits 位操作

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.

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Bit Manipulation

#include <iostream>
using namespace std;
class Solution {
public:
    int hammingWeight(uint32_t n) {
        int sum =0;
        while(n){
            if(n&-n)    sum++;
            n = n&(n-1);
        }
        return sum;
    }
};

int main()
{
    uint32_t n = 11;
    Solution sol;
    cout<<sol.hammingWeight(n)<<endl;
    return 0;
}