[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

 

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#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;

}