COMPLEJIDAD TOSTRING

                                                                       //O(n)
    public String toString(){                      //T=2+max(1,)+1+6+E(3+5)+1
        if (this.esVacia())                                                     //2-
            return ("Lista Vacia");                                             //1
        String r="";                                                            //1
        for(NodoD<T> x=this.cabeza;x!=null;x=x.getSig())                        //6+E(3)
            r+=x.getInfo().toString()+"<->";                                    //5
        return(r);                                                              //1
    }
T=2+max(1,else)+1+6+\sum_{1=0}^{n}(3+5)+1

T = 2+1+1+6+3n+5n+1 = 11+8n

O(n)