Zepto SDE-1 Interview Exp

Round1 DSA:

1. Problem Statement:
   You are programming an autonomous survey drone. You are given an array of terrain elevations of size N, where elevations[i] represent the peak height of sector i. You are also given a maximum thrust limit max_dist.
   The drone follows strict flight safety rules:

• The drone can fly left or right to another sector j such that 1|i-j|max_dist.
• The destination sector j must have a strictly lower elevation than the starting sector i (elevations[j] < elevations[i]).
• The drone cannot fly over any sector between i and j that has an elevation greater than or equal to elevations[i].
• Once the drone lands at a sector, it can launch again from that sector to another valid lower sector, continuing as long as valid moves exist.
  Task:
• Determine the maximum number of sectors the drone can visit in a single continuous flight, assuming you can choose any sector as the starting point.

Constraints:

• 1 <= arr.length <= 1000
• 1 <= arr[i] <= 105 
  arr = [6,4,14,6,15,13,9,7,10,6,12], d = 2

2. There was a code given in Java/Go where some of the logic was incorrect and we have to prepare test cases through LLMs. Basically thinking where the code could fail. Also covering the concurency in the code part. This was like an experiment they were trying out how candidates would perform.

   Understand what it does and how. Be ready to explain it to
   your interviewer in your own words — what each part is for, and why it is built this way. Write your test cases in plain English

   Your interviewer will give you somewhere to write these — a shared document or similar.
   They have to exist before you prompt.
   Agent to implement those test cases. Record every prompt you send, verbatim and in order, in the same place — the log is part of your submission.
   Run them. Something should fail. From that failure, work out what is actually wrong — that is the observation.
   Fix it, yourself or with the agent, and show the tests passing.

Round 2: LLD

Splitwise like system
Group expense
User to user expense
User able to see direct and group expense
Update existing transaction
Create/ Get/ Update