Number of 1 Bits

Number of 1 Bits

Total Accepted: 64907 Total Submissions: 171590 Difficulty: Easy

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.

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