Note: All of these are using C# code examples.
- Hex string to byte array
- Convert a list of strings into a set of enums
- Remove a set of characters from a string
- Join strings with a separator, ignoring nulls and empty strings
- Check if a string contains any substrings from a list
- Set Operations – Intersect, Union, Difference, and Symmetric Difference
- Merge two dictionaries in-place
- Pad a 2D array on all sides
These problems are from algorithm challenge websites (such as codewars).