摘要
设G~σ为简单图G的一个定向.介绍了定向图G~σ的积和多项式,得到了G~σ的积和多项式根据图的结构表示的系数公式,证明了一个图G的所有定向图有相同的积和多项式当且仅当G没有偶圈.对定向图G~σ的积和多项式的根也进行了研究.
Let G~σ be an orientation of a simple graph G.The permanental polynomial of an oriented graph G~σwas introduced and the coefficients of the permanent polynomial of G° were interpreted in terms of the graph structure of G~σ.It was proved that all orientations G~σ of G have the same permanental polynomial if and only if G has no even cycle.The roots of the permanental polynomial of G~σ were studied.
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