Bit Manipulation - Number of 1 Bits (Hamming Weight)
You need to count how many bits are set to 1 in a 32-bit unsigned integer. Which approach guarantees the most efficient and reliable solution regardless of input size?
You need to count how many bits are set to 1 in a 32-bit unsigned integer. Which approach guarantees the most efficient and reliable solution regardless of input size?
easy🔍 Pattern Recognition Q11 of Q15
Step-by-Step Solution
Step 1: Understand problem constraints
The problem requires counting set bits in a fixed-size integer, which can be done in constant time using hardware or built-in functions.Step 2: Compare approaches
Brute force and DP approaches work but are slower (O(1) but with more operations). Greedy subtraction is inefficient and incorrect for bit counting. Built-in functions leverage optimized CPU instructions for O(1) time.Final Answer:
Option B -> Option BQuick Check:
Built-in bit count functions are optimal and reliable [OK]
Quick Trick: Built-in bit count functions use CPU instructions [OK]
Common Mistakes:
MISTAKES- Confusing greedy subtraction with bit counting
- Thinking DP is needed for fixed-size integers
Trap Explanation:
PITFALL- Brute force looks simple and correct but is slower; DP seems overkill but plausible; greedy is incorrect but tempting.
Interviewer Note:
CONTEXT- Tests if candidate recognizes optimal bit counting approach beyond naive methods.
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