Count set bits (Hamming Weight)
Updated Apr 28, 2026
Short answer
Iteratively clear the lowest set bit using n & (n - 1).
Deep explanation
This explores bitwise arithmetic and identity properties. Iteratively clear the lowest set bit using n & (n - 1). These patterns are common in technical coding interviews.
Real-world example
Efficient memory allocation alignment checks.
Common mistakes
- Not handling the case where n = 0 for power-of-two checks.
Follow-up questions
- What is the time complexity?