如果图 G 的一个边着色用了 1,2,…,t 中的所有颜色,并且关联于 G 的同一个顶点的边上的颜色各不相同,且这些颜色构成了一个连续的整数区间,则称这个边着色是 G 的区间 t-着色。如果对某个正整数 t,G 有一个区间 t-着色,则称 G 是可区...如果图 G 的一个边着色用了 1,2,…,t 中的所有颜色,并且关联于 G 的同一个顶点的边上的颜色各不相同,且这些颜色构成了一个连续的整数区间,则称这个边着色是 G 的区间 t-着色。如果对某个正整数 t,G 有一个区间 t-着色,则称 G 是可区间着色的。所有可区间着色的图构成的集合记作 N。图 G 的亏度 def( G)是粘在 G 的顶点上使它可区间着色的悬挂边的最小数目,显然,G∈N 当且仅当 def( G)= 0。广义θ-链是把路 P =[v0,v1,…,v k]( k≥1)的每一条边 vi-1 vi( i = 1,2,…,k),用 mi≥2 条两两内部不交的( vi-1,vi)-路替换掉而得到的简单图,记作θm1,m2,…,mk。把广义θ-图亏度的结论进行推广,确定了θm1,m2,…,mk的亏度。展开更多
A proper edge t-coloring of a graph G is a coloring of its edges with colors 1, 2,..., t, such that all colors are used, and no two adjacent edges receive the same color. A cyclically interval t-coloring of...A proper edge t-coloring of a graph G is a coloring of its edges with colors 1, 2,..., t, such that all colors are used, and no two adjacent edges receive the same color. A cyclically interval t-coloring of a graph G is a proper edge t-coloring of G such that for each vertex, either the set of colors used on edges incident to x or the set of colors not used on edges incident to x forms an interval of integers. In this paper, we provide a new proof of the result on the colors in cyclically interval edge colorings of simple cycles which was first proved by Rafayel R. Kamalian in the paper “On a Number of Colors in Cyclically Interval Edge Colorings of Simple Cycles, Open Journal of Discrete Mathematics, 2013, 43-48”.展开更多
A proper edge t-coloring of a graph G is a coloring of its edges with colors 1,2,???,t such that all colors are used, and no two adjacent edges receive the same color. A cyclically interval t-coloring of a graph G is ...A proper edge t-coloring of a graph G is a coloring of its edges with colors 1,2,???,t such that all colors are used, and no two adjacent edges receive the same color. A cyclically interval t-coloring of a graph G is a proper edge t-coloring of G such that for each its vertex x, either the set of colors used on edges incident to x or the set of colors not used on edges incident to x forms an interval of integers. For an arbitrary simple cycle, all possible values of t are found, for which the graph has a cyclically interval t-coloring.展开更多
文摘如果图 G 的一个边着色用了 1,2,…,t 中的所有颜色,并且关联于 G 的同一个顶点的边上的颜色各不相同,且这些颜色构成了一个连续的整数区间,则称这个边着色是 G 的区间 t-着色。如果对某个正整数 t,G 有一个区间 t-着色,则称 G 是可区间着色的。所有可区间着色的图构成的集合记作 N。图 G 的亏度 def( G)是粘在 G 的顶点上使它可区间着色的悬挂边的最小数目,显然,G∈N 当且仅当 def( G)= 0。广义θ-链是把路 P =[v0,v1,…,v k]( k≥1)的每一条边 vi-1 vi( i = 1,2,…,k),用 mi≥2 条两两内部不交的( vi-1,vi)-路替换掉而得到的简单图,记作θm1,m2,…,mk。把广义θ-图亏度的结论进行推广,确定了θm1,m2,…,mk的亏度。
文摘A proper edge t-coloring of a graph G is a coloring of its edges with colors 1, 2,..., t, such that all colors are used, and no two adjacent edges receive the same color. A cyclically interval t-coloring of a graph G is a proper edge t-coloring of G such that for each vertex, either the set of colors used on edges incident to x or the set of colors not used on edges incident to x forms an interval of integers. In this paper, we provide a new proof of the result on the colors in cyclically interval edge colorings of simple cycles which was first proved by Rafayel R. Kamalian in the paper “On a Number of Colors in Cyclically Interval Edge Colorings of Simple Cycles, Open Journal of Discrete Mathematics, 2013, 43-48”.
文摘A proper edge t-coloring of a graph G is a coloring of its edges with colors 1,2,???,t such that all colors are used, and no two adjacent edges receive the same color. A cyclically interval t-coloring of a graph G is a proper edge t-coloring of G such that for each its vertex x, either the set of colors used on edges incident to x or the set of colors not used on edges incident to x forms an interval of integers. For an arbitrary simple cycle, all possible values of t are found, for which the graph has a cyclically interval t-coloring.
