问题: [单选题]DFS on a graph, which situation means that the graph contains a loop 对图进行DFS,一下哪种情况意味着该图包含环路s0x答案窝(daanwo.com)-大学作业答案分享平台 AThere has a TREE edge 有TREE边s0x答案窝(daanwo.com)-大学作业答案分享平台 BThere has a BACKWARD edge 有BACKWARD边s0x答案窝(daanwo.com)-大学作业答案分享平台 CThere has a FORWARD edge 有FORWARD边s0x答案窝(daanwo.com)-大学作业答案分享平台 DThere has a CROSS edge 有CROSS边