Round 1 (Coding Round) :
There were 2 coding questions carrying 80 and 50 marks.
14 MCQs each of 5 marks most of them being from Operating System.
It was conducted on Interviewbit platform.
- Given an array of integers where each element represents the max number of steps that can be made forward from that element. Write a function to return the minimum number of jumps to reach the end of the array (starting from the first element).
- Given a number n, generate bit patterns from 0 to 2^n-1 such that successive patterns differ by one bit.
Round 2 (F2F Interview) :
The interview asked me to introduce myself. He asked me why I had such low CGPA.
I gave the reason for it. Then he asked me to explain one of the projects and then asked some questions related to it.
After this, he asked me 2 DS/Algo questions.
- Given an array of N integers. Find the next greater permutation of the array.
- Given a binary tree and two values say n1 and n2, find the least common ancestor (LCA).
After discussing the approach I had to code it on paper with all the edge cases covered.
The interviewer was very friendly throughout the process.
The round went for around 45 min.
Round 3 (F2F Interview) :
The Interviewer started with a basic introduction.
He started with a DBMS query. I thought for about 10 min and was discussing with him throughout. Since I was facing difficulty to come up with a correct approach he told me to think about self-join. After 5min I got the hang of it and wrote the query. There were some syntax errors but he was satisfied with the approach.
The query was something like :
Given a table containing the attributes emp_name, emp_id, emp_manager_id. For each employee find the manager name, manager’s manager name.
Then a short discussion on my projects.
After this, he shifted to DS/Algo and asked 2 questions.
1. Find a tour that visits all stations
I struggled a bit to explain my approach since he was expecting some other solution. After he was convinced he told me to write the code.
2. Connect n ropes with minimum cost
I told him the solution using a priority queue and wrote the code. He asked me how a priority queue is implemented.
After this, we had a long discussion on heaps.
1. How it is different from a priority queue.
2. It’s implementation.
3. Build function complexity. I forgot that it takes O( N ) time and told him O( N log N ) instead. Then he asked me to prove that complexity is O( N ).
I somehow convinced him that it is O( N ).
The actual proof is Time Complexity of building a heap
After all of this, he asked me whether I am comfortable with OS.
Questions related to Paging and Indexing were asked.
The round went for about 75 min.
Round 4 (F2F Interview) :
The interviewer started with OS.
What are different types of operating system like Batch operating system.
Process vs Thread and why use threads.
Role of Kernel.
Process Synchronisation. Semaphores vs Mutex.
Then some questions on CN.
TCP vs UDP.
What happens when you type google.com
Then one programming question.
Kth smallest element in a row-wise and column-wise sorted 2D array
After discussing the approach I was asked to write a production code which is clean and bug-free.
Then finally a DBMS query which involved some nesting.
The round went for about 50 min.
1. Keep discussing with the interviewer what you are thinking. The interviewer is keen to know your thought process.
2. Be confident and take your time to understand and solve the problem.
3. Mention only those projects in your resume which you know by heart.