Pn和Cn分别表示具有n个项点的路和圈,Dn表示Pn-2的一个1度点粘接K3的一个点得到的图,应用伴随多项式理论研究了Pl∪Cm∪Dn的补图的色性,刻画了它的所有色等价图,并给出了其色惟一的条件.
Let Pn be the path with n vertices and Cn the cycle with n vertices and let Dn be the graph obtained by ident'flying one vertex of K3 with one of end vertices of Pn-2. All chromatically equivalent graphs of the complement of Pl∪Cm∪Dn are characterized completely, by using theory of adjoint polynomials of graphs. A sufficient condition for it to be chromatically unique is given.