On the Strong Chromatic Number of Graphs

On the Strong Chromatic Number of Graphs

The strong chromatic number, χS(G), of an n-vertex graph G is the smallest number k such that after adding kdn/ke−n isolated vertices to G and considering any partition of the vertices of the resulting graph into disjoint subsets V1, . . . , Vdn/ke of size k each, one can find a proper k-vertex-coloring of the graph such that each part Vi, i = 1, . . . , dn/ke, contains exactly one vertex of ea...

The locating-chromatic number for Halin graphs

Let G be a connected graph. Let f be a proper k -coloring of G and Π = (R_1, R_2, . . . , R_k) bean ordered partition of V (G) into color classes. For any vertex v of G, define the color code c_Π(v) of v with respect to Π to be a k -tuple (d(v, R_1), d(v, R_2), . . . , d(v, R_k)), where d(v, R_i) is the min{d(v, x)|x ∈ R_i}. If distinct vertices have distinct color codes, then we call f a locat...

The locating chromatic number of the join of graphs

‎Let $f$ be a proper $k$-coloring of a connected graph $G$ and‎ ‎$Pi=(V_1,V_2,ldots,V_k)$ be an ordered partition of $V(G)$ into‎ ‎the resulting color classes‎. ‎For a vertex $v$ of $G$‎, ‎the color‎ ‎code of $v$ with respect to $Pi$ is defined to be the ordered‎ ‎$k$-tuple $c_{{}_Pi}(v)=(d(v,V_1),d(v,V_2),ldots,d(v,V_k))$‎, ‎where $d(v,V_i)=min{d(v,x):~xin V_i}‎, ‎1leq ileq k$‎. ‎If‎ ‎distinct...

Strong Chromatic Number of Fuzzy Graphs

On the Strong Chromatic Number of Random Graphs

Let G be a graph with n vertices, and let k be an integer dividing n. G is said to be strongly k-colorable if for every partition of V (G) into disjoint sets V1 ∪ . . . ∪ Vr, all of size exactly k, there exists a proper vertex k-coloring of G with each color appearing exactly once in each Vi. In the case when k does not divide n, G is defined to be strongly k-colorable if the graph obtained by ...