The interview consisted of one technical round, focused on DSA fundamentals + problem-solving depth.
Question 1: Deep Copy of Linked List (with Random Pointer)
The interviewer explored the concept in depth.
My Approach:
→ First explained brute force using HashMap (O(n) space)
→ Then optimized to O(1) space using node interleaving
Follow-ups:
-
What do key & value represent?
→ The original node acts as the key and its copied node as the value. -
Can we do deep copy without extra space?
→ Yes, using the interweaving technique with O(1) auxiliary space. -
Why separate linked lists?
→ To ensure changes in the copied list don’t affect the original. -
Dry Run- hashmap solution.
-
Optimisation & Time Complexity/ Space Complexity
-
Edge cases.
Question 2: Next Higher Rated Movie
Given a list of movies with ratings, find the next movie on the right with a higher rating.
My Approach:
Used Monotonic Stack (Next Greater Element pattern).
Follow-ups:
- Why traverse from right?
- When would brute force fail?
- Can we do it without stack?
It was a concept-heavy and discussion-oriented interview. I suggest two things:
-
You should always have an answer for:
a. Why you're using this DS? what advantage that gives in this PS?
b. Why you're doing this step?
c. Can you optimize this?
d. Run me through a test case.
e. What's the TC/ SC? -
Think aloud clearly.
Upvote if you liked!
All the best to everyone preparing. 💪
