It consisted of 3 coding questions and 10 MCQs (no negative marking). One of the coding question was based on DFAs and Graphs to solve optimization problem. The MCQs were based on a variety of topics like probablity, permutations, code output, complexities, recursion, general aptitude and even some puzzles.
It started with basic introduction. The interviewer asked about my previous summer internship and other projects mentioned in CV in brief.
Then, I was asked 3-4 very easy questions on linked lists and trees. It ended with me asking some questions on working culture and projects offered in the firm.
The interviewer was quite friendly and hence this round went very smooth.
This was the best round!
Initially, it started with some very basic questions like 'What is a computer' followed by moving into hardware stuff and then questions about Operating Systems. I informed the interviewer that I was more proficient in DS and that I had a course on OS in the next sem.
Following this, the next questions were more design based where initially I had to connect alternate nodes of a linked list and then had to customize the solution on some constraints which were modified every time I answered the solution (this lasted around 50 minutes). With increasing complexity, sufficient hints were provided and its the way you approach the solution that gets tested.
It was followed by some interesting puzzles related to general aptitude and ended with more questions that I asked about the firm.
In this round, I was asked just one question which was related to finding the kth most searched query on the internet. It involved coming up with the best data structure to fit given constraints and arriving at the best complexity possible.
I couldn't solve it completely but sufficient hints were provided as and when required. Discussing whatever approaches I had and keeping the conversation flow going helped a lot.
If you feel that you are less proficient in a particular topic and more questions are being asked on it, its always better to convey that frankly to the interviewer rather than screwing the complete interview later.
All the best!