List Problems

1. Find the largest and smallest values without built-ins.
2. Remove duplicates while preserving order.
3. Move all zeroes to the end.
4. Rotate a list by k positions.
5. Find pairs that add up to a target.
6. Merge two sorted lists.
7. Find the missing number from 1 to n.
8. Find the intersection of two lists.
9. Find the maximum sum of a contiguous sub-list.
10. Group values by their frequency.