How do you reverse a string using a stack?
PICTURE THIS: STACK VS QUEUE
Simple meaning
Push every character, then pop them all into a new buffer.
WHY — Stack instead of guessing?
Why interviewers care about Stack:
question about Stack.
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:
- 1Push every character, then
pop them all into a new buffer.
- 2Push and pop are
O(1) each, so total time is O(n) with O(n) extra space.
- 3Two-pointer reverse is better
on a mutable buffer
- 4the stack version mainly
shows you understand LIFO.
- 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
Push every character, then pop them all into a new buffer. Push and pop are O(1) each, so total time is O(n) with O(n) extra space.