Bloomberg Software Engineer interview questions

On Campus interview. Firstly talked about the most interesting project on resume, then 3 coding problems. there are two interviewers, each of them asked 1 to 2 questions. And at the end, I asked some questions.

I applied online and they contacted me after 3-4 weeks asking me to give various available time slots for the phone interview. They scheduled a 45 minutes phone interview. Choosing a programming language of your choice: How do you implement a Polynomial? After I told them Array list, he showed me a very big polynomial and asked me what will you do if you have very big polynomial that needs to be handled? (Using an array list 'll consume hell a lot of memory for polynomials of higher degree) I answered him that i 'll use a hashmap to store the degrees and coefficients. He seemed to be impressed with that. How will you implement the following four functions using the hashmap/arraylist: 1. Constructor which details how your polynomial is stored 2. Adding two polynomials. 3. Printing polynomial. 4. Finding the derivative of the polynomial. He also asked me about my prior work experience and also about my current Master's thesis project which I thought I answered well. But I was able to implement only the first two functions(using arraylist) with in the time limit. Got a rejection email with in 3 days.