■色唯一的充要条件

Necessary and Sufficient Condition of ChromaticUniqueness of ■

Pn和Cn分别表示具有n个顶点的路和圈.Un表示由Pn-4的两个1度点分别与两个P3的2度点粘接得到的图.应用图的伴随多项式理论得到了(∪i∈AUi)∪(∪j∈BPj)∪(∪k∈MCk)色唯一的充要条件.

Let Pn be the path with n vertices and Cn the cycle wirh n vertices and let Un be the graph obtained by identifying two vertices of degree 2 of P3 with two of end vertices of Pn-4. By using theory of adjoint polynomials of graphs, the necessary and sufficient condition of chromatic uniqueness of --（∪↑i∈AUi）∪（∪↑j∈BPj）∪（∪↑k∈MCk） is given.