Number of 1 Bits
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.
Follow up: If this function is called many times, how would you optimize it?
Example 1
Input
n = 11Output
3The input binary string 1011 has a total of three set bits.
Example 2
Input
n = 128Output
1The input binary string 10000000 has a total of one set bit.
Constraints
- 1 <= n <= 2^31 - 1