• Question
• Solution

Question

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.

Solution

Result: Accepted Time: 8 ms

Here should be some explanations.

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

Complexity Analytics

• Time Complexity: $O(log(n))$
• Space Complexity: $O(1)$