Technical Phone interview

This is going to be quick post. I was asked 3 questions.

1) Find the nth last node in a linked list. Had to write the code and read it.

2) Find the intersection of two sorted arrays. Again had to write code and read it. She also asked me to write test cases and complexity for this one.

3) Design a car rental system. I think I floundered here. I answered with three classes
  a) class CarRental  (will have an array of Car objects)
  b) class Car
  c) class Customer

It was a 45 minute interview and this was my second round. I wrote about my first phone interview here . Within one hour after this interview, I got a mail for scheduling 3rd round of phone interview. Usually with this company 2 phone interviews are norm, but I guess, they could not make a decision to call me on-site. Now waiting for 3rd round.