Number of 1 Bits

Easy

Given a non-negative integer n, return the number of set bits (1s) in its binary representation (its Hamming weight).

Example 1

Input:  n = 11
Output: 3
Explanation: 11 = 1011 in binary.

Example 2

Input:  n = 128
Output: 1

Constraints

• 0 <= n <= 2^31 - 1