struct prb_node *y = w->prb_link[1]; y->prb_color = PRB_BLACK; w->prb_color = PRB_RED; w->prb_link[1] = y->prb_link[0]; y->prb_link[0] = w; if (w->prb_link[1] != NULL) w->prb_link[1]->prb_parent = w; w = f->prb_link[0] = y; w->prb_link[0]->prb_parent = w;