My Interview Experience

Published on Thursday, August 24 2017 • 4 minutes read

Let me describe my college interview process. There were a total four rounds:

  • Competitive Online Coding Challenge
  • Pair Coding
  • Technical Interview
  • Final Interview

Competitive Online Coding Challenge

The Coding Challenge was conducted on HackerRank. It consisted of three problems based on Data Structures and Algorithms and were to be solved in 90 minutes.

  1. Speed of Particles

    There are n particles placed on the x axis, which will move along the positive x-axis. If two particles collide, the particles continue moving in the same direction without change in their speeds or direction. Given the speeds of the pariticle and ID of a particle of interest, the number of collisions that this particle will encounter is to be printed.

  2. Selecting a Team

    Given an array of n elements denoting the skill of n employees, a team of t members is to be selected. In every iteration, an employee with the maximum skill is to chosen. The selection is made from groups with m members from the start and end of the array. The sum of the skills of all the selected memebers is to be printed.

  3. S Expression

    Given a list of parent - child pairs of a binary tree, the S Expression of the binary tree is to be printed. In case the pairs provided contain errors like Multiple parents, Duplicate edges, etc., the error associated error codes are to be printed.

I was able to solve the first problem completely and the second problem partially. Marks were provided for partially solved problems based on the number of passed test cases.

Pair Coding

This round was also conducted on HackerRank. It consisted of a single problem to be solved in 75 minutes. But first, you have to explain to one of the interviewers how you would approach the problem and what it is asking, only then can you start writing the code.

Animal Species

There are a total of n animal species. An array of n elements pi is provided which denotes species pi can eat species i. If pi is -1 it means that no species eats species i. Also, there are no transitive relationships. The problem is to group these species in a way that in any group, no species eats the other. The output is the number of groups so that there are minimum number of groups.

Technical Interview

There were two interviewers, one of them concentrated on concepts we had studied in our Engineering Syllabus and the other was focussed on puzzles and practical questions. The following are a few of the technical questions they asked from each of the topics:

  • Data Structures

    • List all the data structures you know.
    • Which is your favorite data structure? Explain it briefly.
    • What sort of Data Structure does Facebook use?
    • What is the difference between a Queue and a Trie.
    • Can you create a hybrid data structure from a Queue and a Trie?

  • Databases

    • What are save points and check points?
    • Explain the different normalization forms.
    • Give an example of an Object Oriented Database.

  • Operating Systems

    • What is the difference between System and Application memory?
    • What is the difference between LRU and MFU?
    • Explain L1, L2 cache concepts.
    • What is thrashing?

  • The Web

    • Give a few HTTP methods.
    • What is caching?

The second interviewer asked a view practical questions:

  • I have n employees living in multiple locations around the city and they all need to reach the office on time. Which algorithm would be best to determine the time taken by each to reach the office?
  • I had placed 10 red and 10 blue socks in a drawer of my cupboard. I have to get ready but the power is down. I can take out one sock at a time and I want to make sure that I have socks of the same color when I walk out to the light. What is the minimum number of socks I should pick?
  • Do you know about LinkedIn? Explain the different types of connections LinkedIn has?

Final Interview

The final interview was a Video Interview. This interview basically focussed on communication skills and how you present your ideas. The interviewer asked a few simple questions that I have listed below:

  • Tell me about yourself.
  • How has your experience been today? How do you feel about the recruitment process today?
  • What sort of programming languages are you comfortable in?
  • Can you summarize in about five minutes, your life experiences and what you would bring to our organization?
  • I see you have done this project in Database Lab. Can you explain it to me how it works and what technologies you have used?
  • Your Computer Graphics project is about Tower of Hanoi. Can you explain it to me as if I'm a layman?

Lastly, a few tips. Be confident and truthful. Try to express your thought process to the interviewer when solving problems and do tell her / him if you are not sure of the answer. I would like to thank the Placement and Training Office of my Institution for giving me this opportunity.