supported by the Scientific Research Fund of Zhejiang Provincial Education Department(Y201226078);The third author was supported partially by NSFC(11071223);ZJNSF(Z6090150)
Supported by the National Natural Science Foundation of China (Grant No. 11071223);the Natural ScienceFoundation of Zhejiang Province (Grant No. Z6090150);Research Project of Zhejiang Educational Committee(Grant No. Y201121311)
A linear coloring of a graph G is a proper vertex coloring such that the graph induced by the vertices of any two color classes is the union of vertex-disjoint paths. The linear chromatic number lc(G) of G is the sm...
Supported partially by the National Natural Science Foundation of China(11071223);the Zhejiang Natural Science Foundation of China(Z6090150);the Foundation of Zhejiang Educational Committee(Y201226078)
In this paper, we prove that every graph with maximum degree six that can be embedded in a surface of nonnegative characteristic is of Class I if it does not contain a 5- or 6-cycle with a chord, which extends some kn...