3D table of constant size

Question

I am asked to create a class that contains a 3D table. However, the size is not standard and are given by the user. I can obviously use a vector, and that would be fine. However, can I make the vector of constant size after initializing it, or is there an alternative to create such an object, without the use of a vector? Thanks in advance

Answer 1

However, can I make the vector of constant size after initializing it

If you don't resize the vector, then its size remains constant. You can make the vector a private member of a class to enforce such restriction with a class invariant.

or is there an alternative to create such an object, without the use of a vector?

You can allocate a dynamic array without using a vector. But it won't be quite as convenient.

Answer 2

You can by using new , but it means a lot of work on your side. Here is a minimal example:

class threeDTable {
  public :
    threeDTable(int n){data = new yourType[n*n*n]; size=n;}
    ~threeDTable(){delete []data;}
    void set(int x, int y, int z, yourType value){data[size*size*x + size*y + z]=value;}
    yourType get(int x, int y, int z)const {return data[size*size*x + size*y + z];}
  private :
    yourType *data;
    int size;
  };