1,110 research outputs found
Characterizing All Trees with Locating-chromatic Number 3
Let be a proper -coloring of a connected graph . Let be the induced partition of by , where is the partition class having all vertices with color .The color code of vertex is the ordered-tuple , where, for .If all vertices of have distinct color codes, then iscalled a locating-coloring of .The locating-chromatic number of , denoted by , isthe smallest such that posses a locating -coloring. Clearly, any graph of order have locating-chromatic number , where . Characterizing all graphswith a certain locating-chromatic number is a difficult problem. Up to now, we have known allgraphs of order with locating chromatic number or .In this paper, we characterize all trees whose locating-chromatic number . We also give a family of trees with locating-chromatic number 4
Trees with Certain Locating-chromatic Number
The locating-chromatic number of a graph G can be defined as the cardinality of a minimum resolving partition of the vertex set V(G) such that all vertices have distinct coordinates with respect to this partition and every two adjacent vertices in G are not contained in the same partition class. In this case, the coordinate of a vertex v in G is expressed in terms of the distances of v to all partition classes. This concept is a special case of the graph partition dimension notion. Previous authors have characterized all graphs of order n with locating-chromatic number either n or n-1. They also proved that there exists a tree of order n, n≥5, having locating-chromatic number k if and only if k ∈{3,4,"¦,n-2,n}. In this paper, we characterize all trees of order n with locating-chromatic number n - t, for any integers n and t, where n > t+3 and 2 ≤ t < n/2
The Asymptotic value of the Locating-Chromatic number of -ary Tree
In 2013, Welyyanti et al. proved that for all
positive integers . In this paper we prove that for any fixed integer
, almost all -ary Tree satisfy ,
moreover .Comment: 4 Pages, 1 figur
The neighbor-locating-chromatic number of pseudotrees
Ak-coloringof a graphGis a partition of the vertices ofGintokindependent sets,which are calledcolors. Ak-coloring isneighbor-locatingif any two vertices belongingto the same color can be distinguished from each other by the colors of their respectiveneighbors. Theneighbor-locating chromatic number¿NL(G) is the minimum cardinalityof a neighbor-locating coloring ofG.In this paper, we determine the neighbor-locating chromatic number of paths, cycles,fans and wheels. Moreover, a procedure to construct a neighbor-locating coloring ofminimum cardinality for these families of graphs is given. We also obtain tight upperbounds on the order of trees and unicyclic graphs in terms of the neighbor-locatingchromatic number. Further partial results for trees are also established.Preprin
On locating-chromatic number of complete n-ary tree
Abstract
Let c be a vertex k -coloring on a connected graph G(V, E) . Let Π = {C1, C2, ..., Ck}
be the partition of V (G) induced by the coloring c . The color code cΠ(v) of a vertex v in
G is (d(v, C1), d(v, C2), ..., d(v, Ck)), where d(v, Ci) = min{d(v, x)|x ∈ Ci} for 1 ≤ i ≤ k.
If any two distinct vertices u, v in G satisfy that cΠ(u) = cΠ(v), then c is called a locating
k-coloring of G . The locating-chromatic number of G, denoted by χL(G), is the smallest k
such that G admits a locating k -coloring. Let T(n, k) be a complete n -ary tree, namely
a rooted tree with depth k in which each vertex has n children except for its leaves. In this
paper, we study the locating-chromatic number of T(n, k
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