What are the errors of this chunk of C code that sums the nodes of a binary tree?

Question

int somaFolha(struct NO **Raiz)
{
  int somaF;

  if (Raiz != NULL)
  {
    if (Raiz->esq == NULL || Raiz->dir == NULL)
      somaF += Raiz->valor;
    else
    {
      somaF = somaFolha((*Raiz).esq);
      somaF += somaFolha(Raiz->dir);
    }
  }

  return somaF;
}

Answer 1

In the case of Raiz was NULL, you are returning garbage, since in this case, folhaF is not being initialized. In this case it is best to return zero.

I also see that you’re wearing ||, but to check if the knot is leaf, it should be &&.

As zentrunix noticed, you are also using struct NO ** when it should just be struct NO *.

Also, I suggest renaming Raiz for raiz and somaFolha for soma_folha in order to conform to the standard of C.

And it makes the code very simple. I suggest that it stays that way:

int soma_folha(struct NO *raiz) {
     if (raiz == NULL) return 0;
     if (raiz->esq == NULL && raiz->dir == NULL) return raiz->valor;
     return soma_folha(raiz->esq) + soma_folha(raiz->dir);
}

If you are a fan of the ternary operator, you can simplify a little more:

int soma_folha(struct NO *raiz) {
     return raiz == NULL ? 0
             : raiz->esq == NULL && raiz->dir == NULL ? raiz->valor
             : soma_folha(raiz->esq) + soma_folha(raiz->dir);
}