Number of 1 Bits

Easy · Bit Manipulation

You are given a non-negative integer. Count how many bits in its binary representation are set to 1. Return that count as an integer.

Examples

Input:  n = 11
Output: 3
Why:    11 in binary is 1011, which has three 1 bits.

Input:  n = 128
Output: 1
Why:    128 in binary is 10000000, which has a single 1 bit.

Input:  n = 0
Output: 0
Why:    0 has no set bits.

Constraints

0 <= n <= 2^31 - 1

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This statement is written for CodeSpeek. The problem is part of the NeetCode 150 list; Watch NeetCode's explanation of Number of 1 Bits. Reference solutions from the NeetCode repository (MIT) are used to verify our tests.