Number of 1 Bits
Easy
Bit Manipulation
Given a positive integer `n`, write a function that returns the number of set bits in its binary representation (also known as the Hamming weight).
Example 1
Input: n = 11
Output: 3
Explanation: The input binary string 1011 has a total of three set bits.
Example 2
Input: n = 128
Output: 1
Explanation: The input binary string 10000000 has a total of one set bit.

Constraints

  • •1 <= n <= 2³¹ - 1
Time Complexity
O(log n)
Space Complexity
O(1)
14
Case 1
Input: 11
Expected: 3
Case 2
Input: 128
Expected: 1
Case 3
Input: 2147483645
Expected: 30