Expedia came to our campus for hiring as both FTE(for 4th year students) and Interns(for 3rd year students).
It first conducted a coding round which had around 10 MCQs from all the topics: Arrays, Linked Lists, Stacks and Queues, Graphs, Time Complexities. Then 2 coding questions. One of Linked List, other of Hashmap.
Around 20 students were shortlisted from the coding round then the interview rounds started.
The interviewer was very humble and he asked me which DS I was comfortable in, whether Trees was okay. I said yes so he started with basic tree traversals and general discussion on trees. Very basic questions.
Then he asked me if I could write an optimised Code for Construction of BST from the traversals given.
I gave him a solution but not the one he wanted, so he dropped a few hints and I wrote the optimised code.
The questions he then asked were as follows: Suppose you have to make a human body, you have things like Arms, Legs, Head etc. Now you want to integrate all these into a single body but then the restrictions of only 2 arms or 2 legs are allowed should also be applicable. I honestly don’t know the answer to this question till date. I used the concepts of OOPs of Inheritance in which every body part was a class and told him whatever popped in my mind.
The next question he asked was: If you have infinite number of tables, but ribbons of only 3 colours. You have to tell me how many tables can you cover. The restrictions being you can’t use the same colours adjacent to each other. The number of ribbons of each type was given. This question had a very easy answer which he told me afterwards. It can easily be solved by taking a few examples. But I gave him a very complicated recursive solution, nevertheless he was impressed with that solution.
Then the HR round happened. In that he gave me two sorted arrays. One had empty spaces in the end and I had to merge them in O(N). It had an easy solution of beginning from the end of both the arrays and updating the first array from the last position.
Questions like “Tell me about yourself”, “Explain this line of your resume or tell me about this project” were common in all the rounds. Every interviewer was very well-mannered and patient even though each round was about an hour long.
So basically, Recursion, Trees, Arrays, OOPS were mostly asked from me in my interview experience. Other students who had different interviewers were asked questions on SQL, OS, Graphs, Linked List, Hashmap as well.