It was a phone interview and a HackerRank assignment.

On the phone, the interviewer described the position and the teams working at Bloomberg. The candidate then had 30 minutes for a coding assignment in any programming language from the HackerRank options, which were provided in advance.

The assignment was to write a function that gets two character arrays: the first is the string and the second is the substring. The function should remove all appearances of the given substring.

Two restrictions apply:

• Memory complexity must be O(1) (no conversion to String or allocation of memory for another array).
• A character cannot be written in the same position more than once (a naive solution would not fit this limit).