@haidangwy , in this post, you confirmed you were a student and your earlier post was part of an assignment. Will it possible for you to share some details re: the class where you have such assignments? Some questions that come to mind are as follows: is it generally on numeric computing? Or is it specific to Fortran programming? If the former, does the class cover any Fortran language teaching at all or are the language details left up to the students to pick up? And is the choice of the solution paradigm (whether what is currently a compiler-based language such as Fortran or more of a modeling platform such as MATLAB) decided for all the students as part of the class requirements or does each student pick their own choice?
The reasons for above questions are some of your Fortran coding practices (or lack thereof) and what might be their origin in this day and age. By the way, are you able to tap into a textbook resource such as Fortran for Scientists and Engineers by Chapman, 2018? I think you will find it very useful to review that book.