FStergeQ

void StergeQ(nod * & prim, nod * & ultim, nod * q)
{
    if(q==prim && q==ultim)
    {
        prim=NULL;
        ultim=NULL;
        delete q;
        return;
    }
    if(q==prim)
    {
        prim=q->pre;
        q->pre->ant=0;
        delete q;
    }
    else if(q==ultim)
    {
        ultim=q->ant;
        q->ant->pre=0;
        delete q;

    }
    else
    {
        q->ant->pre=q->pre;
        q->pre->ant=q->ant;
        delete q;
    }

}