Simply C++ command line utility to compare files; what classes to use?

I have decided that I want to write a simple command line utility to load two files into some C++ class/ADT.

The entries will be package names and the will be different with no duplications. The data from two files files need to be compare and entries missing from being in both files displayed.

The files will contain package_name [WHITE_SPACE] package_version.

I will be ignore package_version and just loading package_name into the ADT.

I just wish a list of classes to check out in doing the ADT; right now the only thing that comes to mind is vector. But, I am still trying to learn C++ and this project seems both useful and simple an a good thing to try.

My last project was too complex and I lost interest when other real world things happened.

I will be using MinGW64 GCC 12.1 and I do not wish to use third party libs like Boost.

Edit: If I was using C, I would use a sorted link list.

Thank you all for your past help.

Tim S.

I think I'd use std::set - cppreference.com

Read the first file into set 1.

When reading the 2nd file, do one of two things
- if it's in set1, it's common to both (so remove it from set1)
- otherwise, add it to set2

The end result is two sets containing only items that appear in one file.