Amazon Interview Experience 1.5 years Experienced

I was contacted by an amazon recruiter for the SDE-1 role.

Coding Round: Two questions were asked to be solved in 105 minutes in which we have to write time complexity and algorithm as well.

1. Given a string which has only ‘(‘, ‘)’, ‘[‘, ‘]’, and ‘?’, Determine numbers of ways by which string can be split into two substrings such that characters in both substrings can form a balanced string. You can replace the question mark with any other 4 characters.

Input - "[(??][??["
Output - 2

2. Given an array that has the amount of rainfall for ith day and an integer k, return indexes(start from 1) of days which are ideal for camping. A day is said to be ideal if the rainfall is in decreasing order prior to considered day and then in increasing order following k days from considered day.

Input - day = [3,2,2,2,3,4], k = 2
Output - [3, 4]

I got a call after a week to schedule the first 3 rounds. All 3 rounds happened on the same day.

Round 1(Technical):

1. https://www.geeksforgeeks.org/find-a-triplet-in-an-array-whose-sum-is-closest-to-a-given-number/
2. https://www.geeksforgeeks.org/shortest-path-in-a-binary-maze/
3. Tell me about time when you dive deeper into understanding a technology that solves a great customer problem and How your solution was better than the previously implemented solution.

Round 2(Technical and Managerial):

1. https://www.geeksforgeeks.org/lru-cache-implementation/
2. How to implement threading in C++
3. How HTTPS protocol works
4. How HTTPS is passed to application via server
5. Detailed Project discussion.
6. Tell me about a time when you solve a major frequent issue that was causing a lot of trouble to customers by observation.
7. Tell me about a time when you have made sacrifices while solving a customer problem
8. How indexing and partitioning helps in optimizing DB queries

Round 3(Technical):

1. Merge 3 sorted  arrays with removed duplicates
2. https://www.geeksforgeeks.org/merge-k-sorted-arrays/
3. https://www.geeksforgeeks.org/subtract-two-numbers-represented-as-linked-lists/
4. Any scenario when you have controversy with someone with team or business or customer is unsatisfied.

Round 4(Bar-Raiser):

1. Given a grid , with persons standing, some are empty spaces, you need to remove minimum number of people to sure that now two people are adjacent to each other(only horizontal and vertical are adjacent).
2. Given a list of heights of building whose width is 1, find max area enclosed by buildings. Ex – [5,2,4,1,1,1,2] – ans is 7. https://www.geeksforgeeks.org/largest-rectangle-under-histogram/
3. Tell me about a time when You deliever something that is quite challenging for you?
4. Tell me about when you took calculated risk?
5. Tell me about a time when you work on tough feedbacks from customer and what to do you learn from it?

All the Best