Routh-Hurwitz Stability Criterion

[FlatAssembler]

What do you think, what is the easiest way to implement the special cases of the Hurwitz algorithm, that is, when one or more elements in a row of the matrix are zero?
The core of my program implementing the Hurwitz Algorithm is this (in AEC, the programming language I designed and implemented):

Code:

Function popuni_matricu() Which Returns Integer16 Does
  Integer16 broj_stupaca :=
              (stupanj_polinoma + 1) / 2 + mod(stupanj_polinoma + 1, 2),
            broj_redaka := stupanj_polinoma + 1;
  Integer16 i := 0;
  //Popunimo matricu prvo not-a-numbersima...
  While i < broj_redaka Loop
    Integer16 j := 0;
    While j < broj_stupaca Loop
      matrica[f(i, j)] := 0. / 0.;
      j += 1;
    EndWhile
    i += 1;
  EndWhile
  //Zatim idemo primjeniti Hurwitzov algoritam...
  i := 0;
  While i < broj_redaka Loop
    Integer16 j := 0;
    While j < broj_stupaca Loop
      If i = 0 Then // Prvi redak
        matrica[f(i, j)] := polinom[j * 2];
      ElseIf i = 1 Then // Drugi redak
        matrica[f(i, j)] := (j * 2 + 1 < stupanj_polinoma + 1) ?
                            polinom[j * 2 + 1] :
                            0;
      Else // Ostali reci...
        If matrica[f(i - 1, 0)] = 0 Then
          //TODO: Implementirati što se radi u posebnim slučajevima...
          Return 0;
        EndIf
        matrica[f(i, j)] := (matrica[f(i - 1, 0)] *
                            (j + 1 < broj_stupaca ?
                             matrica[f(i - 2, j + 1)] : 0) -
                            (matrica[f(i - 2, 0)] *
                            (j + 1 < broj_stupaca ?
                             matrica[f(i - 1, j + 1)] : 0))) /
                            matrica[f(i - 1 , 0)];
      EndIf
      j += 1;
    EndWhile
    i += 1;
  EndWhile
  If matrica[f(broj_redaka - 1, 0)] = polinom[stupanj_polinoma] Then
    Return 1;
  EndIf
  Return 0;
EndFunction

What should be done at the place of TODO, instead of returning an error code? Neso Academy video presents two ways of dealing with that, none of which seem easy to program.