{ "id": "1101.2765", "version": "v2", "published": "2011-01-14T10:51:21.000Z", "updated": "2011-03-08T02:38:08.000Z", "title": "Rainbow connection of graphs with diameter 2", "authors": [ "Hengzhe Li", "Xueliang Li", "Sujuan Liu" ], "comment": "10 pages", "categories": [ "math.CO" ], "abstract": "A path in an edge-colored graph $G$, where adjacent edges may have the same color, is called a rainbow path if no two edges of the path are colored the same. The rainbow connection number $rc(G)$ of $G$ is the minimum integer $i$ for which there exists an $i$-edge-coloring of $G$ such that every two distinct vertices of $G$ are connected by a rainbow path. It is known that for a graph $G$ with diameter 2, to determine $rc(G)$ is NP-hard. So, it is interesting to know the best upper bound of $rc(G)$ for such a graph $G$. In this paper, we show that $rc(G)\\leq 5$ if $G$ is a bridgeless graph with diameter 2, and that $rc(G)\\leq k+2$ if $G$ is a connected graph of diameter 2 with $k$ bridges, where $k\\geq 1$.", "revisions": [ { "version": "v2", "updated": "2011-03-08T02:38:08.000Z" } ], "analyses": { "subjects": [ "05C15", "05C40" ], "keywords": [ "rainbow path", "best upper bound", "rainbow connection number", "minimum integer", "distinct vertices" ], "note": { "typesetting": "TeX", "pages": 10, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2011arXiv1101.2765L" } } }