Problem Statement in English

Approach

This is a subset of this problem.

Solution in Python


class Solution:
    def hammingWeight(self, n: int) -> int:
        ans = 0
        while n > 0:
            if n&1 > 0:
                ans+=1
            n = n >> 1


        return ans

Complexity

  • Time: $O(1)$
    Since we only process $32$ bits at most.

  • Space: $O(1)$
    Since we only store an integer variable.

And we are done.