Let alpha be a set ofnelements and delta be a nonnega-tive integer. A delta-partition of alpha is a set of pairwise disjointnonempty subsets of alpha such that the union of the subsets isequal to alpha and every subse...
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Let alpha be a set ofnelements and delta be a nonnega-tive integer. A delta-partition of alpha is a set of pairwise disjointnonempty subsets of alpha such that the union of the subsets isequal to alpha and every subset has a size greater than *** an algorithm for computing all delta-partitions of agivenn-element set and show that the algorithm runs inn O(n)space and O(n)delaytime between any two succes-sive outputs of delta-partitions of the given set. An applicationof the notion of delta-partitions is illustrated in the followingscheduling problem. Suppose a factory hasnmachines and <= mnjobs to complete daily. Every job can be accom-plished by operating at least+delta 1machines. A machinecannot work on multiple jobs simultaneously. Accordingto a utilization policy of the factory's management, nomachine is allowed to be idle, so all machines should berunning on some job. Find a daily schedule of the factory'smachines satisfying all the mentioned constraints. Let alpha bethe set of the factory's machines. Then, an alpha's delta-partitionwithmsubsets is a legal schedule if every subset (in the delta-partition) includes exclusively+delta 1or more machinesthat run on the same job
Cohesive group extraction is an important task in many applications such as graph visual-ization, system science, and bioinformatics. The k-vertex-connected component (k-VCC), which is a connected graph that remains c...
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Cohesive group extraction is an important task in many applications such as graph visual-ization, system science, and bioinformatics. The k-vertex-connected component (k-VCC), which is a connected graph that remains connected whenever fewer than k vertices are removed, is a well-studied model for this task. However, the use of k-VCC model may cause resolution issues;thus, we use the k-relaxed-vertex connected component (k-RVCC) model, which effectively eliminates the problem. A k-RVCC is also a connected graph, but to disconnect it, at least n -k vertices must be removed, n is the vertex number of the graph. In this study, we investigate efficient practical algorithms for listing all maximal k-RVCCs from a given graph. Specifically, we first adapted the celebrate Bron-Kerbosch tree-search algorithm from listing cliques to listing k-RVCCs. We then design new branch-ing rules to reduce the number of branches and vertex-cut-based strategies to recursively partition the input graph into smaller independent pieces. Implementation techniques that accelerate the aforementioned algorithms were also investigated. Experiments on various large real networks validated the effectiveness of the proposed algorithms and demon-strated the efficiency of our algorithms in mining cohesive groups.(c) 2022 Elsevier Inc. All rights reserved.
For the fundamental problem of enumeration of all simple cycles of a given directed graph with n vertices and m edges, it is known that the delay time between successive outputs of two simple cycles is O(n+m) where m...
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Given a set of directed paths (called lines) L, a public transportation network is a directed graph G (L) = (V (L) , A (L) ) which contains exactly the vertices and arcs of every line l a L. An st-route is a pair (pi,...
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Given a set of directed paths (called lines) L, a public transportation network is a directed graph G (L) = (V (L) , A (L) ) which contains exactly the vertices and arcs of every line l a L. An st-route is a pair (pi, gamma) where gamma = aOE (c) l (1),aEuro broken vertical bar, l (h) > is a line sequence and pi is an st-path in G (L) which is the concatenation of subpaths of the lines l (1),aEuro broken vertical bar, l (h) , in this order. Given a threshold beta, we present an algorithm for listing all st-paths pi for which a route (pi, gamma) with |gamma| ae beta exists, and we show that the running time of this algorithm is polynomial with respect to the input and the output size. We also present an algorithm for listing all line sequences gamma with |gamma| ae beta for which a route (pi, gamma) exists, and show how to speed it up using preprocessing. Moreover, we show that for the problem of finding an st-route (pi, gamma) that minimizes the number of different lines in gamma, even computing an -approximation is NP-hard.
We provide an algorithm for listing all minimal double dominating sets of a tree of order n in time O(1.3248(n)). This implies that every tree has at most 1.3248(n) minimal double dominating sets. We also show that th...
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We provide an algorithm for listing all minimal double dominating sets of a tree of order n in time O(1.3248(n)). This implies that every tree has at most 1.3248(n) minimal double dominating sets. We also show that this bound is tight.
We provide an algorithm for listing all minimal double dominating sets of a tree of order n in time O(1.3248(n)). This implies that every tree has at most 1.3248(n) minimal double dominating sets. We also show that th...
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ISBN:
(纸本)9783319080161;9783319080154
We provide an algorithm for listing all minimal double dominating sets of a tree of order n in time O(1.3248(n)). This implies that every tree has at most 1.3248(n) minimal double dominating sets. We also show that this bound is tight.
We provide an algorithm for listing all minimal 2-dominating sets of a tree of order n in time O(1.3248(n)). This implies that every tree has at most 1.3248(n) minimal 2-dominating sets. We also show that this bound i...
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We provide an algorithm for listing all minimal 2-dominating sets of a tree of order n in time O(1.3248(n)). This implies that every tree has at most 1.3248(n) minimal 2-dominating sets. We also show that this bound is tight.
We disprove a conjecture by Skupien that every tree of order n has at most 2(n/2) minimal dominating sets. We construct a family of trees of both parities of the order for which the number of minimal dominating sets e...
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We disprove a conjecture by Skupien that every tree of order n has at most 2(n/2) minimal dominating sets. We construct a family of trees of both parities of the order for which the number of minimal dominating sets exceeds 1.416(n). We also provide an algorithm for listing all minimal dominating sets of a tree in time O(1.4656(n)). This implies that every tree has at most 1.4656(n) minimal dominating sets. (c) 2013 Elsevier B.V. All rights reserved.
We describe some theoretical results on triangulations of surfaces and we develop a theory on roots, decompositions, and genus surfaces. We apply this theory to describe an algorithm to list all triangulations of clos...
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We describe some theoretical results on triangulations of surfaces and we develop a theory on roots, decompositions, and genus surfaces. We apply this theory to describe an algorithm to list all triangulations of closed surfaces with at most a fixed number of vertices. We specialize-the theory to the case that the number of vertices is at most 11, and we obtain theoretical restrictions on genus surfaces, allowing us to obtain a list of all triangulations of closed surfaces with at most 11 vertices.
An efficient algorithmlisting all minimal vertex separators of an undirected graph is given. The algorithm needs polynomial time per separator that is found.
An efficient algorithmlisting all minimal vertex separators of an undirected graph is given. The algorithm needs polynomial time per separator that is found.
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