From the beginning of the interview, we went straight to the task, with the interviewer presenting me with the problem. I first explained my thought process and the explanation for the optimal solution, but I got the response that it was not clear. So, I was asked to start with a suboptimal solution of O(n^2).

After the implementation, 30 minutes were left, which meant I could try for the optimal solution. However, I was instead asked three questions on modifying my existing code/solution to achieve different results (not the initial problem).

I don't know why we didn't proceed to try the optimal solution for the initial problem, but my experience was that the interviewer was very passive and not interactive. I was expecting that in this kind of interview, there would be a point where I could at least receive a hint, but I didn't receive any.

A bit disappointed at the end for not taking the chance to try, but overall, it was a nice new experience.

Given an array of integers, return the longest subsequence where every next value is 1 bigger than the previous.

This is approximately equivalent to the "Longest Arithmetic Subsequence of Given Difference" problem on LeetCode.