# Nference Interview Experience for SDE

• Difficulty Level : Medium
• Last Updated : 08 Jul, 2020

### Round-1

The first round was an online coding test. This test consists of 2 coding questions and 1 hour to solve them and platform of test was Hackerrank.

#### Problem -1

First problem was very interesting and also standard. How many binary search tree(BST) are possible with given number of keys.

Hey geek! It's time to become a success story instead of reading them. Check out our most renowned DSA Self Paced Course, now at a student-friendly price and become industry ready. And if you are looking for a more complete interview preparation resource, check out Complete Interview Preparation Course that will prepare you for the SDE role of your dreams!

Feeling prepared enough for your interview? Test your skills with our Test Series that will help you prepare for top companies like Amazon, Microsoft, TCS, Wipro, Google and many more!

Solution: This can be done by two method. One way is a DP solution https://www.geeksforgeeks.org/number-of-unique-bst-with-a-given-key-dynamic-programming/

Another way to solve this problem is very easy and answer is just catalyn number. You can refer to https://www.geeksforgeeks.org/total-number-of-possible-binary-search-trees-with-n-keys/

#### Problem -2

Second problem was easy and just the implementation of BFS in a grid. It was something like. Check if there exist a path from cell(0,0) to cell(n,m) in a grid with n rows and m columns in which some cells are blocked.

Around 400 students gave the online test and around 15 -20 got selected for further on-campus interview rounds.

### Round -2 (Technical Interview Round-1)

The interviewer jumped right on asking me some easy coding problems.

1) How will you check if a given binary tree is a BST or not.

https://www.geeksforgeeks.org/a-program-to-check-if-a-binary-tree-is-bst-or-not/

2) Because this is a ML/AI based company and in ML/AI we have to deal a lot with matrices. So he asked me some simple matrices related problems like, Write code for multiplying two matrices etc.

### Round -3(Technical Interview Round-2)

The second interview was already a little impressed with my online test results and first asked me how did you solve both problems so quickly(17-18 mins). Then he began with the problems .

1) First problem was based on using maps .Given two arrays A and B and we need  to print all the elements of array A which are not in array B.

2) I don’t remember the exact problem but it was something with trees and i was not able to write code for that. But i told him an approach for that problem and he was okay with that.

Then he asked me some puzzles and i more or less solved them and overall he was happy with my solutions.

In the end he asked me Why Nference?

### Round -4(HR Round)

The interview began with some compliments like, I have heard nice feedback about you from other interviewers that you are sharp. That boosted my confidence and made me a bit relax.

Now i was expecting some standard questions but he began with something completely different question.

What is the problem that you can think of around you?

At this very moment i realized it is going to be something like case study and i had no practice with case studies so got bit uncomfortable but then i took a deep breathe and gathered myself and we discussed about some problems and used my solutions like population, poverty etc.

#### Tip:- Be confident and relax.

Overall experience was very good. All the interviewers were very nice and helping.

My Personal Notes arrow_drop_up