DE Shaw Internship Interview Experience (On-Campus) 2021
DE Shaw visited our campus (MNIT Jaipur) in the first week of August 2020 for a 2-month software development internship.
Technical Test (90 minutes) | HackerRank:
- Given an array of numbers find the number of triplets such that Ai<Aj<Ak or Ai>Aj>Ak for all (i<j<k). | (O(n^2) or O(n log(n)).
- There are x lions, y tigers, z leopards, and w panthers. Find the number of ways to place them on a line such that no two same animals are adjacent to each other. (0<=x,y,z,w<=51) [DP]
- LCS of three strings
I was able to solve three questions in 40 mins and because of this, I was given very much preference in the interview.
Out of 101 students, 12 were shortlisted for the next round.
Technical Interview | Codepair (HackerRank) | (60 Minutes):
There were two interviewers and both of them were very helpful.
- Given two sorted array of size n and m+n. with n and m elements respectively merge them without using extra space.
- A brief discussion on the project.
- Explain Virtual function (vptr and vtable).
- Multiple Inheritance and Diamond Problem.
- Page replacement algorithm.
- concept of virtual memory.
- Dining Philosopher problem using Semaphore, mutex lock with pseudo code.
- Convert BST to min-heap.
- Puzzle: Magnets are placed linearly, with each magnet to be considered as of point object. each magnet suffers force from its left-sided magnets such that they repel it to the right and vice versa. All forces are repulsive. The force is inversely proportional to distance (1/d, d being the distance). Make a function as shown below that takes n as the number of magnets, and an array of their distance from the origin, which finds all the points along the linear line where net force is ZERO. Distance has to be calculated with the precision of epsilon.
- Median of Stream of Running Integers
- Scheduling (OS)
- Few more questions on OOPS which I don’t remember.
3 students out of 12 were promoted to the next TI. Your coding round score, attitude, confidence, and communication skills matter most. You must have a deep knowledge of at least one language. Read all the articles related to your primary language on geeks for geeks.
Technical Interview 2 (50 Minutes):
There were two interviewers in this round also. They were also very helpful and were providing necessary hints at the relevant times
- Design data structure to implement a text editor. I was made to code following operations ( they often asked to write in the most readable and optimal way )
- Insertion at any location
- Deletion of word from any location
(in between they asked me questions related to any STL library which I used and there internal working)
- How cin and cout work and questions on operator overloading
- Question on malloc and free in C.
- Difference between endl and \n.
- Difference between strongly typed and weakly typed languages, dynamic and static languages, and classify c++ and python based on the same.
- What will happen if I do, int arr; while(true)arr++;
- Question on Inter Process Communication.
- Page replacement algorithm.
- File handling in c++ and what happened if we open a 10gb file in a computer with 4gb RAM.
After this round, only 2 students were selected for the summer internship and I was fortunate enough to be one of them.
If you want then after each round you may ask some questions to the interviewee.
Example You can ask about technologies, languages used in their company, or about the environment.
All questions were available on GeeksForGeeks and it is the best site I found for interview preparation. A big thanks to the whole geeks for geeks team and contributors.