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.

Zhizheng Zhang1, Xiaoli Ye1
1Department of Mathematics, Luoyang Teachers’ College, Luoyang 471022, P. R. China
Abstract:

The purpose of this note is to give two binomial sums with generalized Fibonacci sequences. These results generalize two binomial sums by Kilic and Ionascu in The Fibonacci Quarterly, 48.2(2010), 161-167.

Henry Escuadro1, Futaba Fusgiz-Okamoto2
1Mathematics Department, Juniata College, Huntingdon, PA 16652, USA.
2Mathematics Department, University of Wisconsin-La Crosse, La Crosse, WI 54601, USA.
Abstract:

Let \( G \) be a connected graph of size at least 2 and \( c: E(G) \to \{0, 1, \ldots, k-1\} \) an edge coloring (or labeling) of \( G \) using \( k \) colors (where adjacent edges may be assigned the same color). For each vertex \( v \) of \( G \), the color code of \( v \) with respect to \( c \) is the \( k \)-tuple \( \text{code}(v) = (a_0, a_1, \ldots, a_{k-1}) \), where \( a_i \) is the number of edges incident with \( v \) that are labeled \( i \) (for \( 0 \leq i \leq k-1 \)). The labeling \( c \) is called a detectable labeling if distinct vertices in \( G \) have distinct color codes. The value \( \text{val}(c) \) of a detectable labeling \( c \) of a graph \( G \) is the sum of the colors assigned to the edges in \( G \). The total detection number \( \text{td}(G) \) of \( G \) is defined by \( \text{td}(G) = \min\{\text{val}(c)\} \), where the minimum is taken over all detectable labelings \( c \) of \( G \). Thus, if \( G \) is a connected graph of size \( m \geq 2 \), then \( 1 \leq \text{td}(G) \leq \binom{m}{2} \). We present characterizations of all connected graphs \( G \) of size \( m \geq 2 \) for which \( \text{td}(G) \in \{1, \binom{m}{2}\} \). The total detection numbers of complete graphs and cycles are also investigated.

Sakib A . Mondal1
1Enterprise Analytics Group India Science Lab, General Motors Global R&D, GM Technical Centre India Pvt Ltd, Creator Bldg., ITPL, Whitefield Road, Bangalore – 560 066, INDIA
Abstract:

In this paper we prove that every planar graph without \(5\)- and \(8\)-cycles and without adjacent triangles is \(3\)-colorable.

You Gao1, Liwei Chang2
1College of Science, Civil Aviation University of China, Tianjin,300300, P.R.China
2 College of Science, Civil Aviation University of China, Tianjin, 300300, P.R. China
Abstract:

A new construction of authentication codes with arbitration using singular pseudo-symplectic geometry on finite fields is given. Some parameters and the probabilities of success for different types of deceptions are computed.

Yaping Mao1, Chengfu Ye2
1Center for Combinatorics and LPMC-TIKLC, Nankai University, Tianjin 300071, P. R. China
2Department of Mathematics, Qinghai Normal University, Xining, Qinghai 810008, P. R. China
Abstract:

Two graphs are defined to be adjointly equivalent if their complements are chromatically equivalent. By \( h(G,x) \) and \( P(G,\lambda) \) we denote the adjoint polynomial and the chromatic polynomial of graph \( G \), respectively. A new invariant of graph \( G \), which is the fifth character \( R_5(G) \), is given in this paper. Using this invariant and the properties of the adjoint polynomials, we firstly and completely determine the adjoint equivalence class of the graph \( \zeta_n^1 \). According to the relations between \( h(G,x) \) and \( P(G,\lambda) \), we also simultaneously determine the chromatic equivalence class of \( \overline{\zeta_n^1} \).

Magaowa 1, Wuyungaowa 1
1Department of Mathematics, College of Sciences and Technology, Inner Mongolia University Huhhot 010021, P. R. China
Abstract:

In this paper, we discuss the properties of a class of generalized harmonic numbers \( H_{n,r} \). Using Riordan arrays and generating functions, we establish some identities involving \( H_{n,r} \). Furthermore, we investigate certain sums related to harmonic polynomials \( H_n(z) \). In particular, using the Riordan array method, we explore interesting relationships between these polynomials, the generating Stirling polynomials, the Bernoulli polynomials, and the Cauchy polynomials. Finally, we obtain the asymptotic expansion of certain sums involving \( H_{n,r} \).

Zehui Shao1, Meilian Liang2, Lingiang Pan3, Xiaodong Xu4
1School of Information Science & Technology Chengdu University, Chengdu 610106, China; Key Laboratory of Pattern Recognition and Intelligent Information Processing
2School of Mathematics and Information Science Guangxi University, Nanning 530004, China
3Key Laboratory of Image Processing and Intelligent Control; Department of Control Science and Engineering Huazhong University of Science and Technology, Wuhan 430074, China
4Guangxi Academy of Sciences Nanning, Guangxi 530007, China
Abstract:

We prove that \( F_v(3,5;6) = 16 \), which solves the smallest open case of vertex Folkman numbers of the form \( F_v(3, k; k+1) \). The proof uses computer algorithms.

Muhammad Imran1, A. Q. Baig2
1Center for Advanced Mathematics and Physics (CAMP), National University of Science and Technology (NUST) Sector H-12, Islamabad, Pakistan
2Department of Mathematics, GC University Faisalabad, Pakistan
Abstract:

A family \( \mathcal{G} \) of connected graphs is a family with constant metric dimension if \( \dim(G) \) is finite and does not depend upon the choice of \( G \) in \( \mathcal{G} \). The metric dimension of some classes of plane graphs has been determined in references [3], [4], [5], [12], [14], and [18], while the metric dimension of some families of convex polytopes has been studied in references [8], [9], [10], and [11]. The following open problem was raised in reference [11].

Open Problem [11]: Let \( G \) be the graph of a convex polytope which is obtained by joining the graph of two different convex polytopes \( G_1 \) and \( G_2 \) (such that the outer cycle of \( G_1 \) is the inner cycle of \( G_2 \)) both having constant metric dimension. Is it the case that \( G \) will always have constant metric dimension?

In this paper, we extend this study to an infinite class of convex polytopes obtained as a combination of the graph of an antiprism \( A_n \) [1] and the graph of convex polytope \( Q_n \) [2], such that the outer cycle of \( A_n \) is the inner cycle of \( Q_n \). It is natural to ask for the characterization of classes of convex polytopes with constant metric dimension. Note that the problem of determining whether \( \dim(G) < k \) is an NP-complete problem [7].

Juan Liu1,2, Jixiang Meng2, Xindong Zhang1
1College of Mathematics Sciences, Xinjiang Normal University, Urumgi, Xinjiang, 830054, P.R.China
2College of Mathematics and System Sciences, Xinjiang University, Urumgi, Xinjiang, 880046, P.R. China
Abstract:

Let \(D\) be a digraph with order at least two. The transformation digraph \(D^{++-}\) is the digraph with vertex set \(V(D) \cup A(D)\) in which \((x, y)\) is an arc of \(D^{++-}\) if one of the following conditions holds:(i) \(x, y \in V(D)\), and \((x, y)\) is an arc of \(D\);(ii) \(x, y \in A(D)\), and the head of \(x\) is the tail of \(y\);(iii) \(x \in V(D), y \in A(D)\), and \(x\) is not the tail of \(y\);(iv) \(x \in A(D), y \in V(D)\), and \(y\) is not the head of \(x\).In this paper, we determine the regularity and diameter of \(D^{++-}\). Furthermore, we characterize maximally-arc-connected or super-arc-connected \(D^{++-}\). We also give sufficient conditions for this kind of transformation digraph to be maximally-connected or super-connected.

M. Tariq Rahim1, Ioan Tomescu2
1School of Mathematical Sciences, Government. College University, 68-B New Muslim Town, Lahore, Pakistan
2 Faculty of Mathematics and Computer Science, University of Bucharest, Str. Academiei, 14, 010014 Bucharest, Romania
Abstract:

For a graph \(G\) and any two vertices \(u\) and \(v\) in \(G\), let \(d_G(u,v)\) denote the distance between them and let \(diam(G)\) be the diameter of \(G\). A multi-level distance labeling (or radio labeling) for \(G\) is a function \(f\) that assigns to each vertex of \(G\) a positive integer such that for any two distinct vertices \(u\) and \(v\), \(d_G(u,v) + |f(u) – f(v)| = diam(G) + 1\). The largest positive integer in the range of \(f\) is called the span of \(f\). The radio number of \(G\), denoted \(rn(G)\), is the minimum span of a multi-level distance labeling for \(G\).

A helm graph \(H_n\) is obtained from the wheel \(W_n\) by attaching a vertex of degree one to each of the \(n\) vertices of the cycle of the wheel. In this paper, the radio number of the helm graph is determined for every \(n \geq 3\): \(rn(H_3) = 13\), \(rn(H_4) = 21\), and \(rn(H_n) = 4n + 2\) for every \(n \geq 5\). Also, a lower bound of \(rn(G)\) related to the length of a maximum Hamiltonian path in the graph of distances of \(G\) is proposed.

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