【摘要】 G的列表着色是指V(G)的一个颜色安排使得每个点从给定的列表L(v)中得到一个颜色并且使相邻的点染不同的颜色.L(G)=(L(v)v∈V(G))称为G的颜色列表.如果G满足一个列表着色,且每个列表中包含k种颜色,则称G是k-可选择的.本文证明了围长为4的无6-,7-和8-圈的平面图是3-可选择的.更多还原

【Abstract】 A list coloring of G is an assignment of colors to V(G) so that vertex v receives a color from a prescribed list L(v) of colors and adjacent vertices receive distinct colors.is called a color list of G.The graph G is called kchoosable if G admits a list coloring for all color lists L with k colors in each list.In this paper,it is proven that plane graph of girth no less than 4 without 6-,7-and 8-cycles is 3-choosable.更多还原