How do you compute the diameter of a binary tree?
PICTURE THIS: HOW TO EXPLAIN IT
Simple meaning
The diameter is the max of left_height + right_height over every node (in edges).
WHY — Trees instead of guessing?
Why interviewers care about Trees:
question about Trees.
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:
- 1The diameter is the
max of left_height + right_height over every node (in edges).
- 2DFS returns height while
updating a global max
- 3each node is visited
once: O(n) time and O(h) space.
- 4Computing height separately per
node would be O(n^2).
- 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
The diameter is the max of left_height + right_height over every node (in edges). DFS returns height while updating a global max