60 minute time limit:
- Recursively reverse a string: https://leetcode.com/problems/reverse-string
- 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…) - Remove all prime numbers from a linked list. (no mention of how large numbers could be)