The whole process was online.
All the interviews were help via HackerRank CodePair Platform in our TPC office since they did not visit the campus.
Online Round :
There were a total of 32 questions divided as:
Section 1 – 15 MAT/ Logical Reasoning questions. ( MCQs )
Section 2- 15 Technical Questions ( again MCQs but mostly were to determine the output )
Section 3- 2 Coding questions.
1st Question: https://stackoverflow.com/questions/21077763/smallest-number-that-can-not-be-formed-from-sum-of-numbers-from-array
I don’t remember the second question.
Solving one coding question and doing well in other two sections ( each section has its own cut off ) were enough to proceed for Technical Interviews.
Round 1:
1. Asked a bit from my Resume. Did not go into detail.
2. Check if a Binary Tree is BST or not
- First told him that we could check if the inorder traversal is in increasing order ( assuming all unique elements ) we can easily tell. But since I would make use of an array so extra space complexity would be added. So I suggested going for another approach.
- Told him the range approach. He was satisfied but asked me if we can improve the space complexity in Inorder approach. I said we can actually just store the previous element and keep a condition in the Inorder code. He was satisfied and asked me to code the function.
- Asked me to do some changes in the code
3. Main concepts of OOPS
- Told all 4 with examples. Asked me to demonstrate Runtime Polymorphism with an example code.
Round 2:
1. Asked me what technologies I know. I mentioned Django along with some. Asked to briefly explain what is Django.
2. Let us assume we have a library where books aren’t sorted in the racks. You have to design a library software such that:
You can search with multiple keywords ( later I asked if all the keywords should be contained in book name )
You have to output weighted results. For example : If you keyword is “Tom” and there is a book which contains “Tom” in its name 3 times and rest books just once, it should output the book name containing 3 “Tom”s first and then the rest.
- First Approach: Let’s assume we have an array of strings where the strings are book names. For every keyword, treating it as a pattern, we do KMP with every string and also keep a count how many times it was repeated. Then, we would have a refined list and we can iteratively check every keyword in a similar fashion on the refined lists. Then he asked about the weightage part. I said we could make an evaluator function accordingly and maybe we could keep sum of occurences of each keyword as our evaluator function for weightage. Then he asked me the drawback. ( Time complexity obviously )
- Second Approach : Used trie . He asked me how would the trie look like. Explained him with hand gestures since on the screen it was looking more like Linked List. He asked me a few questions on how would we implement it using Trie and what benefit it would give. I figured that conventional Trie wouldn’t be the best so we might need to do some changes to conventional Trie he asked me to show the changes by writing its node and how would I use it. I thought he wasn’t convinced enough so he changed the question.
3. Difference between void pointer and int pointer. What happens to the following operations. ++ on void poiter and ++ on int pointer ( I answered both the parts wrong I guess ).
4. If we can typecast a void pointer why do we need int pointers etc. Told him something but I wasn’t really sure.
5. SQL query involving joins which used group by and limit.
6. What is Virtualization in OS?
Round 3:
1. A = { 1, 4, 6, 8, 9, } ( any random numbers, can be 10^6 as well ). There is a number B = 2 ^ A[0] + 2 ^ A[1] + …
We need to tell at what locations would be have set bits in binary representation of B? ( can be n bit, not 32 /64 )
- Used the concept 2 ^ m is equal to 1 << m. So problem reduces to handling multiple set bits at same location when the numbers in the array would be repeated.
2. What is Abstract Class. What is the use of it?
3. Why can’t we make objects of Abstract Class ( couldn’t answer )
4. What is Virtualization? What is the page size we should use for every process?
HR Round:
Two candidates (including me) were shortlisted for the HR Round. We both were invited to the same online video meeting where the HR told us they’re offering both of us and explained about the company.
Cheers!