How do you check if a positive integer is a power of two using bits?
PICTURE THIS: OOP PILLARS
Simple meaning
A power of two has exactly one bit set, so n > 0 and (n & (n - 1)) == 0.
WHY — Bit Manipulation instead of guessing?
Why interviewers care about Bit Manipulation:
question about Bit Manipulation.
trade-offs, and what you would actually do on a DSA project - not buzzwords.
Name the idea, why it exists, then one short example.
End with when you use it and one common pitfall.
STEPS — What happens step by step?
Before you speak the answer, walk the interviewer through these steps:
- 1A power of two
has exactly one bit set, so n > 0 and (n & (n - 1)) == 0.
- 2That is O(1) time
and O(1) space.
- 3Looping with modulo 2
is O(log n) and is the slower explanation if they want a non-bit backup.
- 4Give an example
One tiny concrete case you can say aloud.
- 5Common mistake
What juniors usually get wrong.
- 6Close
When you pick this over the alternative.
EXAMPLE — See it in action
Here's a short line you can speak, broken into clear beats:
Note: Adapt this scaffold to your own project — keep it under 60–90 seconds.
Key takeaway
A power of two has exactly one bit set, so n > 0 and (n & (n - 1)) == 0. That is O(1) time and O(1) space.