Utilitas Algorithmica (UA)

ISSN: xxxx-xxxx (print)

Utilitas Algorithmica (UA) is a premier, open-access international journal dedicated to advancing algorithmic research and its applications. Launched to drive innovation in computer science, UA publishes high-impact theoretical and experimental papers addressing real-world computational challenges. The journal underscores the vital role of efficient algorithm design in navigating the growing complexity of modern applications. Spanning domains such as parallel computing, computational geometry, artificial intelligence, and data structures, UA is a leading venue for groundbreaking algorithmic studies.

Zhiwen Wang1,2, Jaeun Lee2, Jingwen Li3, Fei Wen3
1School of Mathematics and Computer Science, Ningxia University, Yinchuan, 750021, P.R.China.
2Department of Mathematics of Yeungnam University, Daedong, Kyongsan, Kyongbuk, 712-749, Korea
3Department of Mathematics, Lanzhou Jiaotong University, Lanzhou, 730070, P.R.China
Abstract:

A proper total coloring of a graph \(G\) is called Smarandachely adjacent vertex total coloring of graph if for any two adjacent and distinct vertices \(u\) and \(v\) in \(G\), the set of colors assigned to the vertices and the edges incident to \(u\) doesn’t contain the set of colors assigned to the vertices and the edges incident to \(v\), vice versa. The minimal number of colors required for a Smarandachely adjacent vertex total coloring of graph is called the Smarandachely adjacent vertex total chromatic number of graph. In this paper, we define a kind of \(3\)-regular Multilayer Cycle \(Re(n,m)\) and obtain the Smarandachely adjacent vertex total chromatic number of it.

S. Bonvicini1, G. Mazzuoccolo2
1Dipartimento di Scienze Sociali Cognitive e Quantitative, Universita di Modena e Reggio Emilia, via Allegri 9, 42100 Reggio Emilia (Italy)
2Dipartimento di Matematica, Universita di Modena e Reggio Emilia, via Campi 213/B, 41100 Modena (Italy)
Abstract:

A perfectly one-factorable (PIF) regular graph \(G\) is a graph admitting a partition of the edge-set into one-factors such that the union of any two of them is a Hamiltonian cycle. We consider the case in which \(G\) is a cubic graph. The existence of a PIF cubic graph is guaranteed for each admissible value of the number of vertices. We give conditions for determining PIF graphs within a subfamily of generalized Petersen graphs.

K. Uslu1, N. Taskara1, H. Kose1
1Selcuk University, Science Faculty, Department of Mathematics, 42075, Campus, Konya, Turkey
Abstract:

In this paper, we give the generalization \(\{G_{k,n}\}_{n\in N }\) of \(k\)-Fibonacci and \(k\)-Lucas numbers. After that, by using this generalization, some new algebraic properties on these numbers have been obtained.

Abstract:

Let \(K_q(n, R)\) denote the least cardinality of a \(q\)-ary code of length \(n\), such that every \(q\)-ary word of length \(n\) differs from at least one word in the code in at most \(R\) places. We use a method of Blass and Litsyn to derive the bounds \(K_4(5,2) \geq 14\) and \(K_4(6,2) \geq 32\).

T.Aaron Gulliver1
1T.A. Gulliver is with the Department of Electrical and Computer Engineering, Uni- versity of Victoria, Victoria, BC Canada, V8W 3P6
Abstract:

Let \(d_{q}(n,k)\) be the maximum possible minimum Hamming distance of a linear \([n, k]\) code over \(\mathbb{F}_q\). Tables of best known linear codes exist for all fields up to \(q = 9\). In this paper, linear codes over \(\mathbb{F}_{11}\) are constructed for \(k\) up to \(7\). The codes constructed are from the class of quasi-twisted codes. These results show that there exists a \((78,8)\) arc in \(\text{PG}(2,11)\). In addition, the minimum distances of the extended quadratic residue codes of lengths \(76\), \(88\) and \(108\) are determined.

Italo J. Dejter1
1Department of Mathematics University of Puerto Rico, Rio Piedras, PR 00931-3355
Abstract:

The distribution of distances in the star graph \( S{T_n} \) (\(1 < n \in \mathbb{Z}\)) is established, and subsequently a threaded binary tree is obtained that realizes an orientation of \( S{T_n} \) whose levels are given by the distances to the identity permutation, via a pruning algorithm followed by a threading algorithm. In the process, the distributions of distances of the efficient dominating sets of \( S{T_n} \) are determined.

Mostafa Blidia1, Rahma Lounes1, Mustapha Chellali1, Frédéric Maffray2
1LAMDA-RO Laboratory, Department of Mathematics, University of Blida, B.P. 270, Blida, Algeria.
2CNRS, Laboratoire G-SCOP, 46, avenue Félix Viallet, $803! Grenoble Cedex, France.
Abstract:

A set \(D\) of vertices in a graph \(G = (V, E)\) is a locating-dominating set if for every two vertices \(u, v\) in \(V \setminus D\), the sets \(N(u) \cap D\) and \(N(v) \cap D\) are non-empty and different. We establish two equivalent conditions for trees with unique minimum locating-dominating sets.

Abdollah Khodkar1, Kurt Vinhage2
1Department of Mathematics University of West Georgia Carrollton, GA 30118
2Department of Mathematics Florida State University Tallahassee, FL 32306
Abstract:

Let \( [n]^* \) denote the set of integers \(\{-\frac{n-1}{2}, \ldots, \frac{n-1}{2}\}\) if \(n\) is odd, and \(\{-\frac{n}{2}, \ldots, \frac{n}{2}\} \setminus \{0\}\) if \(n\) is even. A super edge-graceful labeling \(f\) of a graph \(G\) of order \(p\) and size \(q\) is a bijection \(f : E(G) \to [q]^*\), such that the induced vertex labeling \(f^*\) given by \(f^*(u) = \sum_{uv \in E(G)} f(uv)\) is a bijection \(f^* : V(G) \to [p]^*\). A graph is super edge-graceful if it has a super edge-graceful labeling. We prove that total stars and total cycles are super edge-graceful.

K. Reji Kumar1, Gary MaCgillivray2, R. B. BAPaT3
1Department of Mathematics N.S.S College, Pandalam – 689 501 India
2Department of Mathematics and Statistics University of Victoria, BC Canada
3Department of Mathematics Indian Statistical Institute New Delhi, India
Abstract:

A total dominating function (TDF) of a graph \( G = (V, E) \) is a function \( f : V \to [0,1] \) such that for all \( v \in V \), the sum of the function values over the open neighborhood of \( v \) is at least one. A minimal total dominating function (MTDF) \( f \) is a TDF such that \( f \) is not a TDF if the value of \( f(v) \) is decreased for any \( v \in V \). A convex combination of two MTDFs \( f \) and \( g \) of a graph \( G \) is given by \( h_\lambda = \lambda f + (1-\lambda)g \), where \( 0 < \lambda < 1 \). A basic minimal total dominating function (BMTDF) is an MTDF which cannot be expressed as a convex combination of two or more different MTDFs. In this paper, we study the structure of the set of all minimal total dominating functions (\(\mathfrak{F}_T\)) of some classes of graphs and characterize the graphs having \(\mathfrak{F}_T\) isomorphic to one simplex.

Terry A. McKee1
1Department of Mathematics & Statistics Wright State University, Dayton, Ohio 45435 USA
Abstract:

Vertex elimination orderings play a central role in many portions of graph theory and are exemplified by the so-called `perfect elimination orderings’ of chordal graphs. But perfect elimination orderings and chordal graphs enjoy many special advantages that overlap in more general settings: the random way that simplicial vertices can be chosen, always having a choice of simplicial vertices, the hereditary nature of being simplicial, and the neutral effect of deleting a simplicial vertex on whether the graph is chordal. A graph metatheory of vertex elimination formalizes such distinctions for general vertex elimination and examines them with simple theorems and delineating counterexamples.

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