How do you find the maximum product of a contiguous subarray that may contain negatives and zeros?
PICTURE THIS: ARRAY IN MEMORY
Index starts at 0. Scan once for max — O(n).
Simple meaning
Track both the max and min product ending at i because a negative can flip min to max.
WHY — Arrays instead of guessing?
Why interviewers care about Arrays:
question about Arrays.
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:
- 1Track both the max
and min product ending at i because a negative can flip min to max.
- 2Update from the previous
pair times nums[i] or starting fresh at nums[i].
- 3One O(n) pass and
O(1) space.
- 4Zeros reset the running
products, which you should mention.
- 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
Track both the max and min product ending at i because a negative can flip min to max. Update from the previous pair times nums[i] or starting fresh at nums[i].