Graph Subcolorings: Complexity and Algorithms
Graph Subcolorings: Complexity and Algorithms
复制标题
图的子着色:复杂性和算法
DOI:
10.1007/3-540-45477-2_15
复制
发表时间:
2001
期刊:
影响因子:
2.3
通讯作者:
Eike Seidel
中科院分区:
文献类型:
--
作者:
J. Fiala;K. Jansen;V. B. Le;Eike Seidel
In a graph coloring, each color class induces a disjoint union of isolated vertices. A graph subcoloring generalizes this concept, since here each color class induces a disjoint union of complete graphs. Erd?os and independently Albertson et al. proved that every graph of maximum degree at most 3 has a 2-subcoloring. We point out in this paper that this fact is best possible with respect to degree-constraints by showing that the problem of recognizing 2-subcolorable graphs with maximum degree 4 is NP-complete, even when restricted to triangle-free planar graphs. Moreover, in general, for fixed k, recognizing k-subcolorable graphs is NP-complete on graphs with maximum degree at most k2. In contrast, we show that, for arbitrary k, k-SUBCOLORABILITY can be computed efficiently on graphs of bounded treewidth and on cographs.