منابع مشابه
Coloring signed graphs using DFS
We show that depth first search can be used to give a proper coloring of connected signed graphs G using at most ∆(G) colors, provided G is different from a balanced complete graph, a balanced cycle of odd length, and an unbalanced cycle of even length, thus giving a new, short proof to the generalization of Brooks’ theorem to signed graphs, first proved by Máčajová, Raspaud, and Škoviera.
متن کاملColoring Signed Graphs
This survey paper provides an introduction to signed graphs, focusing on coloring. We shall introduce the concept of signed graphs, a proper coloring, and basic properties, such as a balanced graph and switchings. We will examine the chromatic number for six special signed graphs, upper bound the chromatic number, and discuss practical applications of signed graphs.
متن کاملColoring graphs using topology
Higher dimensional graphs can be used to color 2dimensional geometric graphs G. If G the boundary of a three dimensional graph H for example, we can refine the interior until it is colorable with 4 colors. The later goal is achieved if all interior edge degrees are even. Using a refinement process which cuts the interior along surfaces S we can adapt the degrees along the boundary S. More effic...
متن کاملMore Equienergetic Signed Graphs
The energy of signed graph is the sum of the absolute values of the eigenvalues of its adjacency matrix. Two signed graphs are said to be equienergetic if they have same energy. In the literature the construction of equienergetic signed graphs are reported. In this paper we obtain the characteristic polynomial and energy of the join of two signed graphs and thereby we give another construction ...
متن کاملWeak signed Roman domination in graphs
A {em weak signed Roman dominating function} (WSRDF) of a graph $G$ with vertex set $V(G)$ is defined as afunction $f:V(G)rightarrow{-1,1,2}$ having the property that $sum_{xin N[v]}f(x)ge 1$ for each $vin V(G)$, where $N[v]$ is theclosed neighborhood of $v$. The weight of a WSRDF is the sum of its function values over all vertices.The weak signed Roman domination number of $G...
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ژورنال
عنوان ژورنال: Optimization Letters
سال: 2015
ISSN: 1862-4472,1862-4480
DOI: 10.1007/s11590-015-0962-8