给定无向简单图G=(V,E)与颜色集C,并且对C中的每一种颜色。设定一个费用值w(c)∈R^*.全染色是给出图的一个可行染色使得相关联的边和点、相邻的点或边都染不同的颜色.定义了费用全染色问题,即求解最优的全染色f,使得染色费用和x∈v(c)JE(G)w(f(x))最小,时于树图T,给出了一个2-近似算法,该算法的运行时间为O(nΔ^2).
Let G be a simple graph, C be a set of colors, and let w be a cost function which assigns a real number w(c) to each color c in C. A total-coloring of a graph G is to color all the elements of V(G) U E(G) in such a way that no two adjacent or incident elements receive the same color. A 2-approximate algorithm is given to find an optimal cost total-coloring of a given tree T, that is, a total-coloring f of T such that the sum of costs w(f(x)) of colorsf(x) assigned to all elements x is minimum among all total-colorings of T. The algorithm takes time O( nΔ^2 ) if n is the number of vertices and Δ is the maximum degree of T.