I had a brief call with HR and after that they scheduled a half an hour call with the technical team lead.

He explained about the job and the projects they are working on. After that he asked about my experience and at the end asked one technical question.

He was very nice despite the fact that I wasn't very good.

Your program have to support following operations:

1. Receive a character as an input and add it to all previous characters that were sent to this method

2. Remove list of characters from index x till index y

3. Print all the remaining elements in the order they were sent

All 3 methods can be used more than one time, and in any order the user wants

Example:

add(a) add(b) add(c) add(d) remove (2-3) print - the result should be ad

He wanted to see what data structure will I pick for the initial (naive) implementation and what will be the complexity for every action.

After that he asked me to try and make it a little bit more efficient.