## Abstract We show that the following problem is __NP__ complete: Let __G__ be a cubic bipartite graph and __f__ be a precoloring of a subset of edges of __G__ using at most three colors. Can __f__ be extended to a proper edge 3‐coloring of the entire graph __G__? This result provides a natural co
The chromaticity of complete bipartite graphs with at most one edge deleted
✍ Scribed by C. P. Teo; K. M. Koh
- Publisher
- John Wiley and Sons
- Year
- 1990
- Tongue
- English
- Weight
- 364 KB
- Volume
- 14
- Category
- Article
- ISSN
- 0364-9024
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
Let K(p, q), p ≤ q, denote the complete bipartite graph in which the two partite sets consist of p and q vertices, respectively. In this paper, we prove that (1) the graph K(p, q) is chromatically unique if p ≥ 2; and (2) the graph K(p, q) ‐ e obtained by deleting an edge e from K(p, q) is chromatically unique if p ≥ 3. The first result was conjectured by Salzberg, López, and Giudici, who also proved the second result under the condition that q ‐ p ≤ 1.
📜 SIMILAR VOLUMES
## Abstract Let __ex__~2~(__n, K__) be the maximum number of edges in a 2‐colorable __K__‐free 3‐graph (where __K__={123, 124, 134} ). The 2‐chromatic Turán density of __K__ is \documentclass{article}\footskip=0pc\pagestyle{empty}\begin{document}$\pi\_{2}({K}\_{4}^-) =lim\_{{n}\to \infty} {ex}\_{2}