hi guys, I have a question for C++ learners and developers, recently I was doing a test from IT company to get a C++ course

Question

I learned a basic paradigm of C++ and OOP and other things like pointers, structures ,functions,but during my studying I didn’t face with tasks like in this test and codes as well , for example what does mean these triple constructors? these weird structures, set ,vectors.
Where can I learn these topics, how does it call?
I have to prepare for another try! please help me guys what should I learn to understand and perform this type of tasks!!!

there is code

https://code.sololearn.com/cA5a10a17A8a/?ref=app

Answer 1

thank you very much for your help Martin!!!

Answer 2

that course is for ensuing internship , is there in sololearn C++ course these essential topics like sets vectors,lists?