I met with a recruiter during a career fair and submitted my resume. Two weeks later, I received an email to schedule a telephonic interview.

I then scheduled a telephonic interview, during which I would be given a link to HackerRankX, a code pairing website where the interviewer could share their screen with me. It contains a scratchpad and a coding environment.

I was given a question on LinkedLists: flattening a 2D Linked List. At the beginning of the interview, the interviewer dived into my resume. I had mentioned a project on Visual C++, and they asked me to explain it.

They then asked for my approach to the problem. I fumbled for a bit but eventually gave them the algorithm. They asked me to go ahead and code the algorithm I had mentioned. The interviewer was more keen on the edge cases. They asked me to write a function that takes the head as an input parameter.

I solved the question in about 20 minutes. In the remaining time, the interviewer explained the nature of the work at Bloomberg and gave me a chance to ask any questions. Overall, the interview went well.

The next day, I received a rejection email. They did not mention any specific reason for the reject.

Flatten a 2D linked list.

A node contains three parameters: data, a pointer to left, and a pointer to down. The aim of the function is to flatten the linked list.

Example: 1 --> 2 --> 4 | V 3

Answer: 1 --> 2 --> 3 --> 4

Example: 1 --> 2 --> 3 --> 4 | 5 --> 6 --> 7 | 8 9

Answer: 1 --> 2 --> 5 --> 8 --> 6 --> 9 --> 7 --> 3 --> 4

He asked me to flatten the same linked list, not to create a new one or print the elements.