In this paper, Euler's formula and Handshaking lemma is used to obtain the face chromatic number of a planar graph by solving equations.
本文在前人研究的面着色问题基础上,运用欧拉公式和握手定理通过解方程组得到连通平面图的面色数。
Some upper bounds of the edge number for two class planar graphs are given. Some sufficient conditions for a planar graph to be class 1 are obtained through these bounds of edge number.
给出了平面图为第一类图的边数的一些上界,并给出了平面图为第一类图的一些充分条件。
Using this method can be based on signal spectral analysis method of fault diagnosis into a planar graph recognition.
利用该方法可以将基于信号频谱分析的故障诊断方法转化为平面图形的识别。
Secondly, we investigate the list coloring of planar graphs, and give a su? Cientcondition for a planar graph being 3-choosable.
其次,文章研究了平面图的列表着色问题,给出了平面图3 -可选的一个充分条件。