Perl, generating new data (new hash) using two different hash tables

I've bumped into a very complicated problem (in my perspective as a newbie) and I'm not sure how to solve it. I can think of the workflow but not the script.

I have file A that looks like the following: Teacher (tab) Student1(space)Student2(space)..

Fiona       Nicole Sherry 
 James       Alan Nicole
 Michelle    Crystal 
 Racheal     Bobby Dan Nicole
 

They sometimes have numbers right next to their names when there are two of the same name (ex, John1, John2). Students may also overlap if they have more than two advisors..

File B is a file that has groups of teachers together. It looks similar but the values are comma-delimited.

Fiona       Racheal,Jack
 Michelle    Racheal
 Racheal     Fiona,Michelle
 Jack        Fiona
 

The trend in file B is that a key has multiple values and each value becomes a key as well to easily find who is grouped with who.

The output I would like is which students will be likely to receive similar education based on their teacher/groups.So I would like the script to do the following:

1. Store file A into a hash and close



2. Open file B, go through each teacher to see if they have students (some may not, the actual list is quite big..). So if I take the first teacher, Fiona, it will look in stored file A hash table to see if there is a Fiona. If there is, (in this case, Nicole and Sherry), pop them each as new keys to a new hash table.

   
   
   

   while (<Group>) {
        chomp;
        $data=$_;
        $data=~/^(\S+)\s+(.*)$/;
        $TeacherA=$1;
        $group=$2; 
    




3. Then, look at the group of teachers who are grouped with Fiona (Racheal, Jack). Take 1 person at a time (Racheal)

   
   
   

   if (defined??) {
        while ($list=~/(\w+)(.*)/) {
            $TeacherB=$1;
            $group=$2;
    



4. Look at file A for Racheal's students.


5. Fill them as values (comma-delimited) for student keys made from step 2.



6. Print student-student and teacher-teacher group.

   
   
   

   Nicole  Bobby,Dan,Nicole    Fiona   Racheal
    Sherry  Bobby,Dan,Nicole    Fiona   Racheal
    

   
   
   

   Since the next teacher in Fiona's group, Jack, didn't have any students, he would not be in this results. If he had, for example, David, the results would be:

   
   
   

   Nicole  Bobby,Dan,Nicole    Fiona   Racheal
    Sherry  Bobby,Dan,Nicole    Fiona   Racheal
    Nicole  David               Fiona   Jack
    Sherry  David               Fiona   Jack
    

I'm so sorry for asking such a complicated and specific question. I hope other people who are doing something like this by any chance may benefit from the answers.
Thank you so much for your help and reply. You are my only source of help.

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