Thread: Arbitrarily large vector class

In my homework they ask for any large vector in 2 dimensions. I need to implement multiplication operation.

Code:

#include <iostream>
#include <vector>
using namespace std;

class TDVect {
private:
  unsigned int row;
  unsigned int column;

  double TDvect[row][column];

public:
   TDVect(unsigned int A, unsigned int B) {
    row = A;
    column = B;
  } 
  unsigned int getLength() {  //to do: parameterize, return number of row or columns
    return row;
  }
  unsigned int getWidth() {
    return column;
  }
  double getElement(unsigned int i, unsigned int j) {
    return TDVect[i][j];
  }
  void setElement(unsigned int i, unsigned int j, double x) {
    TDVect[i][j] = x;
  }
};

class V:public TDVect {
  V():TDVect(1, 2) {
}};

class M:public TDVect {
  M():TDVect(2, 2) {
}};

V multiplication(V F, M G)
{                               //to do: row times column
  V vmid();
  vmid.setElement(0, 0, F[0][0] * G[0][0] + F[0][1] * G[1][0]);
  vmid.setElement(0, 1, F[0][0] * G[0][1] + F[0][1] * G[1][1]);
  return vmid;
}

int main()
{
  TDVect vectobjA(-1, +9);      //expected error; not given
  cout << vectobjA.getLength() << " ";
  return 0;
}

I'm getting quite a few errors in VScode :
E0245,EO254,E0040,E0028.
I guess the errors are related to each other but I dont understand them.
We did't have STD::Vector in the lectures.