C++ code please add comments where needed

There are a few problems with my code that I need it to be fixed:

Here is the link to all 3 of the problems I currently have: https://docs.google.com/document/d/13VuCspnXBlRD9NruX9pJi-OWv50aRMiNdugzZTg1i6g/edit?usp=sharing

The link to the code: https://docs.google.com/document/d/1MlyOzoOBkOBs7tzqemYK1qp-IzJqNMZQfsB0hmHMo2g/edit?usp=sharing