Paytm Interview Experience for Software Engineer Intern | On-Campus 2020
College: Mtech from one of the top NIT (On Campus)
Location: Gurgaon, India
Date: 11 Nov 2020
Online Assessment: 3 Coding questions in 70 min
Given a new number system according to which:
0->9 1->8 2->7 and son on till 9->0 Input: 420 Convert this number to the new number Output: 579
Print all nodes that are at distance k from a leaf node. In this question. We have to print the sum of all nodes.
Those who did all three questions were shortlisted for the next round. 76 shortlisted.
Technical Interview 1(50 mins):
- A simple recursive function to trace and print all the elements.
- Given two unsorted linked lists. Merge them and in sorted order.
- Given tree. Find if it is a BST.
- Oops, and C++ concepts like abstract classes, virtual classes, virtual function, inheritance,
- Two classes base and derived class. If the object of the derived class is created, what are order constructor and destructor calls?
- And few DBMS questions about DML, DDL, etc.
I did both the coding questions and answers almost all the theory questions perfectly as per my knowledge.
Technical Interview 2 (Worst Experience of my Life -15mins):
- Difference between Windows and Linux? I did tell some differences, but he wanted to discuss monolithic and microkernels, etc. I did not know them in deep.
- Do you know java? I said no, and then I started bragging about if you don’t know java you can’t survive in the IT industry bla…blaa blaaa. Although I said I am ready to learn any technology, language when needed. In reply, he said prove to me that you can do it, and was like how do I prove it. LoL.
- After I already told him I don’t know java, His second question was…Tell me the difference between Java and C++ and I was shocked, he rocked. ):
- Tell me the difference between C and C++.
- Discuss the complexity of quick sort and merge sort. I told the Worst case for quicksort is O(n2) and the average case is O(nlogn) and merges sort O(nlogn) for average as well as worst. And then you know what he replied? He: No, you are saying the opposite. The worst case of quicksort is O(n2) and the average case is O(nlogn). And for merge sort O(nlogn) for average as well as worst. Again I was shocked and he rocked!
- Asked some more irrelevant questions and then said, you don’t know anything.
- And finally, he asked, Do you know LRU Cache? Can u implement it?
I told him the approach, using queue(as a doubly-linked list) and Hash. And he replied you don’t know about DS/Algo too. Again I was shocked and he rocked. I tried asking what was wrong with my approach, but he said bye and cut the call.
Sad reacts only. He rejected almost all students in the 2nd round who have him as a panel.
15 students got the offer.(12 Btech+3 Mtech)