在 C++ 中使用指向对象的指针数组

Question

I need to save objects as pointers in dynamic array but i have problem. This is my code, there are three classes and i need to have array (arrayoftwo) of poiters to class Two that would work further with class Three and so on. I have two problems. One is that i cant figure out how to dynamically allocate space for my arrayoftwo (which i need to dynamically resize by number of stored pointers) and second problem is how to exactly store pointers to objects without destroying object itself. Here is my code:

#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <iostream>
using namespace std;

class One {
public:
    bool addTwo(int a);

private:
    void getspace(void);
    class Two {
    public:
        int a;
    private:

        class Three {
            /*...*/
        };
        Three arrayofThree[];

    };
    int freeindex;
    int allocated;
    Two *arrayoftwo[];
};

void One::getspace(void){
    // how to allocate space for array of pointers ?
    arrayoftwo=new *Two[100];
    allocated=100;
}
bool One::addTwo(int a){
    Two temp;
    temp.a=a;
    getspace();
    arrayoftwo[freeindex]=&temp;
    freeindex++;
    return true;
    //after leaving this method, will the object temp still exist or pointer stored in array would be pointing on nothing ?
}

int main() {
    bool status;
    One x;
    status = x . addTwo(100);
    return 0;
}

Thank you for any help.

EDIT: I cant use vector or any other advanced containers

Answer 1

temp will not exist after leaving addTwo ; the pointer you store to it is invalid at that point. Instead of storing the object as a local variable, allocate it on the heap with new:

  Two* temp = new Two();

To allocate an array of pointers:

  Two** arrayoftwo;  // declare it like this
  // ...
  arrayoftwo = new Two*[100];

And getspace should either be passed a (from addTwo ) or a should be stored as the member variable allocated and getspace should access it from there. Otherwise it's assuming 100 .