Amazon | SDE2 | Bangalore | Interview Exp + Comp

Online Assessment

Q1

You are given a singly linked list with an even number of elements. You need to find the maximum sum of the i-th node from the start and the i-th node from the end — i.e., max(first + last, second + second-last, ...).

• A note in the question mentioned solving this in O(1) space.
• However, all test cases passed with an O(n) space solution.
• For the O(1) space solution, you can reverse the second half of the list and iterate from both ends.

Q2

You're given:

• An array of numerical strings of length n
• A bit string of length n

Each step consists of:

1. Selecting an element from the array if its corresponding bit is 1.
2. Modifying the bit string such that the i-th bit becomes 1 if the (i-1)-th bit is 1.

You need to perform m such steps and return the lexicographically largest string you can obtain.

Honestly, the question was quite confusing. Took me a while to even understand what they were asking. The mathematical notation didn’t help either.

• The problem essentially boils down to selecting the largest number each step and updating the bit string accordingly.
• A naive solution works in O(m * n).
• I was able to pass 7/14 test cases, rest were TLE.
• A max heap may help optimize this further.

If anyone comes across this question online, please share — I’d love to give it another try.

DSA Round

You are given a tree where one node is on fire. You need to compute the time taken for all nodes to catch fire.

• Included 2 leadership principles (LPs).

LLD Round

Design an e-commerce order notification system

• Included 2 LPs

I didn’t emphasize much on low-level details like class diagrams or DB schema. Despite that, the recruiter said the feedback was very positive.
Your mileage may vary (YMMV).

HLD Round

Design a car maintenance workshop management portal

• Included 2 LPs

I was a bit flustered initially, but the interviewer was really kind and helped me gather my thoughts.

Bar Raiser Round

Another DSA problem + 2 LPs

You're given a set of tasks, each with:

• A profit
• A deadline (in time units)
• Each task takes 1 unit of time

You need to schedule tasks to maximize total profit.

I fumbled quite a bit here. Started with a greedy approach, which the interviewer (politely) refuted.
Eventually came up with a DP solution, dry-ran it, and the interviewer seemed satisfied.
But honestly, the final solution I wrote wasn’t correct.

Every interview included two LP questions. The questions themselves I don't remember, but I felt my responses were strong and to the point.