The second round was taken by Principal Software Engineer. He had a communication problem and wasn't able to express clearly what he wanted as a solution. He asked me 2 questions.
1. Given an array, divide it in half at the midpoint and convert it into two stacks, one for the first half and second for the other half. Design a class such that it contains push and pop methods. Push method will take argument A or B for the first and second half respectively along with the value to be pushed. If A the value should be pushed to the first half. Similarly pop would take the argument A or B. If B, it should pop a value from the second half.