Bit Manipulation - Number of 1 Bits (Hamming Weight)
Suppose you need to count the number of 1 bits in a stream of 64-bit integers at very high throughput. Which follow-up approach would best optimize performance?
Suppose you need to count the number of 1 bits in a stream of 64-bit integers at very high throughput. Which follow-up approach would best optimize performance?
hard🎤 Interviewer Follow-up Q10 of Q15
Step-by-Step Solution
Solution:
Step 1: Consider throughput and input size
64-bit integers and high throughput require very fast counting.Step 2: Evaluate options
Brute force and Brian Kernighan's are slower; memoization helps but limited by chunk size.Step 3: Best approach
Hardware instructions or SIMD parallelism provide fastest bit counting at scale.Final Answer:
Option B -> Option BQuick Check:
Hardware-accelerated bit counting is fastest for large-scale streams [OK]
Quick Trick: Use hardware or SIMD for high throughput bit counting [OK]
Common Mistakes:
MISTAKES- Relying on software loops only
- Ignoring hardware acceleration options
Trap Explanation:
PITFALL- Candidates often overlook hardware instructions that drastically improve performance.
Interviewer Note:
CONTEXT- Tests knowledge of practical optimization beyond algorithmic basics.
Master "Number of 1 Bits (Hamming Weight)" in Bit Manipulation
Want More Practice?
15+ quiz questions · All difficulty levels · Free
Free Signup - Practice All QuestionsMore Bit Manipulation Quizzes