It was of 45 minutes. There were 2 questions asked.

1. Given a string, return the lexicographically largest substring. (1<= N <= 100).
2. Given a sorted array and an integer k, group the elements into k groups such that the sum of max element - min element for all the groups is minimum. (1 <= k <= N <= 2*10^5)

I was able to solve the first question completely and the second question partially.