for (int i=0; i < SomeValue; i++)
{
    Class_P *p; //parent class

    int SomeID;

    p = (Class_p)* some_param;
    SomeID = p->getID;

##</code><code>##

class SystemCase{
    public:
        SystemCase getInstance(Class_P *p){
            switch(p->getID()){
                case FIRST_CASE:
                    return FirstCase(p);
                ...
        }
 
        virtual SomeArrayType runMethod();
};

class FirstCase{
    public:
       SomeArrayType runMethod(){ ... }
};

##</code><code>##

for (int i=0; i < SomeValue; i++)
{
    Class_P *p; //parent class

    int SomeID;

    p = (Class_p)* some_param;
    //SomeID = p->getID() isn't needed since we look at this in SystemCase
    SystemCase sc = SystemCase::getInstance(p); 
    SomeArray[i].value = sc.runMethod();
}