Duration: 60 minutes

Question 1: Recursively reverse a string: https://leetcode.com/problems/reverse-string
Question 2: Print a number vertically with each digit on its own line, without converting to a string.
eg. 12345 becomes:
1
2
3
4
5
(note you can do this problem just fine without needing a list or recursive stack...)

Question 3: Remove all prime numbers from a linked list. (no mention of how large numbers could be)