Number Of One Bits

Number Of One Bits bit manipulation

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.

Number Of One Bits Solution

public class NumberOfOneBits {
    // you need to treat n as an unsigned value
    public int hammingWeight(int n) {
        if(n == 0) {
            return 0;
        }

        int count = 0;

        while(n != 0) {
            count += (n) & 1;
            n >>>= 1;
        }

        return count;
    }
}

Last modified October 4, 2020