短语词组短语chordal bipartite graph 弦二部图strongly chordal graph 强弦图1 -chordal graph 弦图-chordal graph 弦图3 -chordal graph 弦图non -chordal graph 非弦图2 -chordal graph 弦图complement of chordal graph 弦图的补图 返回 chordal graph