Expedia visited Our Campus for both Full timers And interns and I was sitting for an intern. The Process Consisted Of an online test Rounds followed by 3 interview rounds.
Online Coding Test (1 Hr 30 min)
They had 0 cut off and the test was conducted on HackerRank.
The test consisted of 10 MCQs and 2 coding questions.
MCQs were revolving around OS, OOPs, Data Structures and algorithms.
The coding questions were as follows:
- You have a total of n coins that you want to form in a staircase shape, where every k-th row must have exactly k coins. Given n, find the total number of full staircase rows that can be formed. ( even binary search was giving TLE for some test cases only O(1) solution could pass all the test cases )
- Given a road where an infinite number of cars can drive. Index of the road is starting for 0 to n. There are m cars whose starting and ending indexes are given in the form of 2 arrays. We have to find the maximum gap where the cars never traveled. ( This question also had a good time and memory constraints )
Round 1: Technical Interview (1Hr – 1Hr 30 min)
Firstly she asked me to introduce myself and tell a few things which are not mentioned in my CV.
Then asked me a coding question:
Given a sorted and rotated array and an element, find the index of that element in a completely sorted array. (This question involved dealing with a lot of cases, finding if the array is left rotated or right rotated, then finding the point of rotation and then index of given element all by binary search. I was asked to code all this)
While I was writing the code of the above question she asked me
- what is runtime and dynamic polymorphism?
- Is JAVA a completely object-oriented programming language.
- and some questions related to OS which I don’t remember (I think this was to check how good you are at multi-tasking)
The next question was:
Find the Number Occurring Odd Number of Times in an array
(I gave her a solution with O(n^2) using 2 loops, a solution in O(n) using Hashmap and XOR solution which runs in O(n). Then she asked me if I can think of a solution with O(1) space complexity and less than 0(n) time complexity)
Then a lot of questions on hashmaps:
- What is hashing
- Which data structure is used in hashmaps
- How is c++ STL map designed/ internal functioning of hash maps
- Design your own Hashmap
A number is represented in Linked List such that each digit corresponds to a node in the linked list. Add 1 to it. I was asked to code this.
Then this question was modified as: A number is represented in Linked List such that a few digits corresponds to a node in the linked list. Add 1 to it. Example: a number 2323499 is represented as 23->2->349->9 should have an output as
23->2->350->0 ( the number of digits in each node is uneven and the result should have the same number of digits in each node as given node.)
Then a puzzle: 10 coins puzzle
The last question was:
Reverse a stack without using extra memory. I was asked to tell the approach and then write the code.
Round 2: Technical Interview (45 min – 1Hr)
The interview started with a general introduction and some discussion on my hobbies.
Then asked me to tell the approach and write algo for the DP question: Maximum size square sub-matrix with all 1s
Next question was same as : Minimum time required to rot all oranges given in geeksforgeeks with a slight change in the language. This is to be solved with BFS.
Along with this, she asked me a lot of questions, some were:
- How do compiler assign memory addresses to variables
- What is memory
- How does URL work
- The significance of writing HTTPS in URL
- What are DNS servers
- What all errors I have encountered in a compiler and the reason behind those errors
- What all sorting algorithms you have used. Can you write code for heapsort and quicksort code?
Then she asked me what all I know about the company and gave me a real-life problem: Given flights starting and terminating stops for e.g.: Delhi to Mumbai, Delhi to Lucknow, Mumbai to Goa, Lucknow to Madurai, Madurai to Goa. Asked me about the data structure I will prefer and then how to optimize flight bookings i.e. find a flight lets say from Delhi to Goa with a minimum number of stops in between.
All this was concluded with the famous rope puzzle:
HR Round (45 min – 1 Hr)
This was the most interesting interview and was taken by the director. I really had fun during this. Firstly the interviewer asked me about my projects mentioned in my CV and its real-life applications.
Most of my projects were in ML so he gave me some real-life problems industry face in performing validation on data.
Then we had a 20 min long discussion on working of Amazon Recommender Systems. Then he asked me to suggest a couple of new features in Amazon based on ML/AI that can improve their business.
Followed by a little discussion on how Machine Learning can be used to give a good experience to tourists.
At last, he asked me about how I see myself growing up in the coming years.
Finally, he asked me if I had any question for him.
Results were announced after a few hours and I was selected 🙂
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