Im having trouble with a homework i was hoping someone can help me , it has to deal with recursions

Question

Recursions,

Answer 1

You cna find the file in chegg, if anyone is willing to help

Answer 2

ok now what do you want to calculate with the function, please specify.

mistakes i found so far,
1. main function is empty (big mistake)
2. everything is written outside of any function (bigger mistake)
3. c++ doesn't have default statement in if and else

many more mistakes, but first clear these first

ref: https://code.sololearn.com/c24it2hYbun5/?ref=app