摘要
一个无割点的外平面图称为开外平面图,如果它的每一个内面的边界至少含一条外边,本文证明了:若G为开外平面图,则(i)当△(G)=3时,X_23(G)=4,当△(G)≥5时,X_23(G)=△(G);(ii)当△(G)=2,4时,4≤X_23(G)≤5,其中X_23(G)为平面图G的边面全色数,△(G)是G的点最大度。
An outerplanar graph without cut vertex is called an open outerplanargraph if the boundary of its each inner face contains at least an outedge.In this paper,weprove that if G is an open outerplanar graph,then(i)X_23(G)=4for△(G)=3,and X_23(G)=△(G)for△(G)≥5;(ii)4≤X_23(G)≤5 for△(G)=2,4,where X_23(G)is the edgeface total chromatic number of G and △(G)is maximam degree of vertices in G.
出处
《辽宁大学学报(自然科学版)》
CAS
1995年第2期1-7,共7页
Journal of Liaoning University:Natural Sciences Edition
基金
辽宁大学青年科学基金
关键词
边面全色数
开外平面图
顶点最大度
平面图
edge face total chromatic number,open outerplanar graph,maximurndegree of vertices.