Neetcode: Number of 1 Bits

Instructions

You are given an unsigned integer n. Return the number of 1 bits in its binary representation.

You may assume n is a non-negative integer which fits within 32-bits.

Example 1:

Input: n = 00000000000000000000000000010111

Output: 4

Example 2:

Input: n = 01111111111111111111111111111101

Output: 30