Oriented graph coloring
نویسنده
چکیده
An oriented k-coloring of an oriented graph G (that is a digraph with no cycle of length 2) is a partition of its vertex set into k subsets such that (i) no two adjacent vertices belong to the same subset and (ii) all the arcs between any two subsets have the same direction. We survey the main results that have been obtained on oriented graph colorings.
منابع مشابه
An oriented coloring of graphs with maximum average degree less than
An oriented k-coloring of an oriented graph G is a homomorphism from G to an oriented graph H of order k. We prove that every oriented graph with maximum average degree less than 10 3 has an oriented chromatic number at most 16. This implies that every oriented planar graph with girth at least five has an oriented chromatic number at most 16, that improves the previous known bound of 19 due to ...
متن کاملAn oriented coloring of planar graphs with girth at least five
An oriented k-coloring of an oriented graph G is a homomorphism from G to an oriented graph H of order k. We prove that every oriented graph with maximum average degree strictly less than 10 3 has an oriented chromatic number at most 16. This implies that every oriented planar graph with girth at least 5 has an oriented chromatic number at most 16, that improves the previous known bound of 19 d...
متن کاملA practical algorithm for [r, s, t]-coloring of graph
Coloring graphs is one of important and frequently used topics in diverse sciences. In the majority of the articles, it is intended to find a proper bound for vertex coloring, edge coloring or total coloring in the graph. Although it is important to find a proper algorithm for graph coloring, it is hard and time-consuming too. In this paper, a new algorithm for vertex coloring, edge coloring an...
متن کاملOn-Line Coloring of Oriented Graphs
A graph coloring algorithm that immediatly colors the vertices taken from a list without looking ahead or changing colors already assigned is called an one-line coloring algorithmm. We study in this paper on-line oriented coloring algorithms. Firstly, we investigate the First-Fit algorithm and we try to characterize the F F-optimall graphs that is the graphs for which there exists a linear orde...
متن کاملAnalogues of cliques for oriented coloring
We examine subgraphs of oriented graphs in the context of oriented coloring that are analogous to cliques in traditional vertex coloring. Bounds on the sizes of these subgraphs are given for planar, outerplanar, and series-parallel graphs. In particular, the main result of the paper is that a planar graph cannot contain an induced subgraph D with more than 36 vertices such that each pair of ver...
متن کامل-λ coloring of graphs and Conjecture Δ ^ 2
For a given graph G, the square of G, denoted by G2, is a graph with the vertex set V(G) such that two vertices are adjacent if and only if the distance of these vertices in G is at most two. A graph G is called squared if there exists some graph H such that G= H2. A function f:V(G) {0,1,2…, k} is called a coloring of G if for every pair of vertices x,yV(G) with d(x,y)=1 we have |f(x)-f(y)|2 an...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Discrete Mathematics
دوره 229 شماره
صفحات -
تاریخ انتشار 2001