How do you choose between vector and deque?
PICTURE THIS: ARRAY IN MEMORY
Index starts at 0. Scan once for max — O(n).
Simple meaning
vector for contiguous dense arrays
WHY — STL instead of guessing?
Why interviewers care about STL:
question about STL.
trade-offs, and what you would actually do on a C++ 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:
- 1Define it
vector for contiguous dense arrays
- 2deque for efficient growth
at both ends.
- 3How it works
Most code starts with vector.
- 4Give an example
Benchmark before clever containers.
- 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
vector for contiguous dense arrays deque for efficient growth at both ends.