@[快乐的水鬼pyke](/user/254733) 都可以，强连通分量不影响；双连通分量只能用 dfn。 by 白鲟 @ 2020-12-08 18:23:46
@[白鲟](/user/67952) 谢谢 by Night_Bringer @ 2020-12-08 18:57:14