Initialize the element of multidimensional array

Question

I've problem with Initialize the element of multidimensional array.

Here's my code:

    class A{
    int *const e;   
    const int row, column;  
public:
    A::A(int r, int c) : row(r), column(c), e(new int[r*c]) 
    {
        for (int i = 0; i < r*c; i++)
        {
            e[i] = 0;
        }
    }

    A(const A &matrix) : row(matrix.row), column(matrix.column) ,e(new int[matrix.row*matrix.column])   
    {
        for (int i = 0; i < matrix.row*matrix.column; i++)
        {
            e[i] = matrix.e[i];
        }
    }
    virtual ~A()        //destructing a A
    {
        delete[] e;
    }
};

But when I'm trying Initialize the element of multidimensional array I've got a error:

int main(int argc, char* argv[])
{
    A c(2, 5);
    c[0][0] = 1;
    A a(c);
    return 0;
}

1 IntelliSense: no operator "[]" matches these operands operand types are: MAT [ int ]

Edit: According to comments I try to write operator []

virtual int *const operator[ ](int r)
{
    return e[r][0];
}

It should get first element of the r row. But I've got a error:

1 IntelliSense: expression must have pointer-to-object type

Answer 1

You're trying to apply the [] to the class A, C++ only knows how to use the operator [] on arrays. In order to use them for A you have to tell how [] works for A, so inside your class definition you should put:

int *operator[](int x){
    return &e[x*row];
}

It basically receives the number you have put between brackets, and returns the corresponding row(an array), so you can apply [] again easily, so for example:

c[0] returns the first row

c[0][1] access the second element of the first row