How does one provide solutions for subtasks in ZCO/INOI problems?

Hi guys, I am currently preparing for ZCO 2023, and I have started doing some past practise papers.

I have some confusions on how to solve subtasks - for example, ZCO22001 problem has the following subtasks -

image

Am I supposed to provide 8 different solutions? Or a universal solution, having 8 conditions? Like for example, I know the solutions for Subtasks 4, 6 & 7. Do I submit my code like this -

int a;
int q;
cin >> a >> q;

if (q <= 5) {
    //respective solution for Subtask 4
} else if(n==1) {
    //respective solution for Subtask 6
} else if(n<=5) {
    //respective solution for Subtask 7
}

What is the solution submission process in ZCO? This is my first attempt of ZCO, so I am a bit confused… Please guide me… Thanks!