Influence maximization is the problem of finding k seed nodes in a given network as information sources so that the influence cascade can be maximized. To solve this problem both efficiently and effectively, in this p...
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ISBN:
(纸本)9783319701394;9783319701387
Influence maximization is the problem of finding k seed nodes in a given network as information sources so that the influence cascade can be maximized. To solve this problem both efficiently and effectively, in this paper we propose LAIM: a linear time algorithm for influence maximization in large-scale social networks. Our LAIM algorithm consists of two parts: (1) influence computation;and (2) seed nodes selection. The first part approximates the influence of any node using its local influence, which can be efficiently computed with an iterative algorithm. The second part selects seed nodes in a greedy manner based on the results of the first part. We theoretically prove that the time and space complexities of our algorithm are proportional to the network size. Experimental results on six real-world datasets show that our approach significantly outperforms other state-of-the-art algorithms in terms of influence spread, running time and memory usage.
For every fixed surface S, orientable or non-orientable, and a given graph G, Mohar (STOC'96 and Siam J. Discrete Math. (1999)) described a linear time algorithm which yields either an embedding of G in S or a min...
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ISBN:
(纸本)9780769534367
For every fixed surface S, orientable or non-orientable, and a given graph G, Mohar (STOC'96 and Siam J. Discrete Math. (1999)) described a linear time algorithm which yields either an embedding of G in S or a minor of G which is not embeddable in S and is minimal with this property. That algorithm, however, needs a lot of lemmas which spanned six additional papers. In this paper, we give a new linear time algorithm for the same problem. The advantages of our algorithm are the following: 1. The proof is considerably simpler: it needs only about 10 pages, and some results (with rather accessible proofs)from graph minors theory, while Mohar's original algorithm and its proof occupy more than 100 pages in total. 2. The hidden constant (depending on the genus g of the surface S) is much smaller It is singly exponential in g, while it is doubly exponential in Mohar's algorithm. As a spinoff of our main result, we give another linear time algorithm, which is of independent interest. This algorithm computes the genus and constructs minimum genus embed dings of graphs of bounded tree-width. This resolves a conjecture by Neil Robertson and solves one of the most annoying long standing open question about complexity of algorithms on graphs of bounded tree-width.
We present a deterministic lineartime and space algorithm for ordered partition of a set T of n integers into n(1/2) sets T-0 <= T-1 <= ... T-n1/2 (-) (1), where vertical bar T-i vertical bar = theta(n(1/2)) an...
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ISBN:
(纸本)9783319196473;9783319196466
We present a deterministic lineartime and space algorithm for ordered partition of a set T of n integers into n(1/2) sets T-0 <= T-1 <= ... T-n1/2 (-) (1), where vertical bar T-i vertical bar = theta(n(1/2)) and T-i <= Ti+1 means that max T-i <= min Ti+1.
Given a graph G=(V,E) and a positive integer p≤|E|. The Line Subgraph Problem is: Is there a subset E'?E such that |E'|≥p and H=(V,E) is a line graph. In this paper, we design a linear time algorithm to solv...
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ISBN:
(纸本)9781510833890
Given a graph G=(V,E) and a positive integer p≤|E|. The Line Subgraph Problem is: Is there a subset E'?E such that |E'|≥p and H=(V,E) is a line graph. In this paper, we design a linear time algorithm to solve the line subgraph problem for Halin graphs. The algorithm is optimal.
We study the Betweenness problem. We are given a set of vertices and betweenness constraints. Each betweenness constraint of the form x similar to {y, z} requires that vertex x lies between vertices y and z. Our goal ...
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We study the Betweenness problem. We are given a set of vertices and betweenness constraints. Each betweenness constraint of the form x similar to {y, z} requires that vertex x lies between vertices y and z. Our goal is to find a vertex ordering that maximizes the number of satisfied constraints. In 1995, Chor and Sudan designed an SDP algorithm that satisfies half of all constraints in a satisfiable instance. We present a simple combinatorial linear time algorithm with the same approximation guarantee. (C) 2012 Elsevier B.V. All rights reserved.
A maximal clique of G is a clique not properly contained in any other clique. A k-clique-coloring of a graph G is an assignment of k colors to the vertices of G such that no maximal clique with at least two vertices i...
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A maximal clique of G is a clique not properly contained in any other clique. A k-clique-coloring of a graph G is an assignment of k colors to the vertices of G such that no maximal clique with at least two vertices is monochromatic. The smallest integer k admitting a k-clique-coloring of G is called clique-coloring number of G. Cerioli and Korenchendler (Electron Notes Discret Math 35:287-292, 2009) showed that there is a polynomial-timealgorithm to solve the clique-coloring problem in circular-arc graphs and asked whether there exists a linear-timealgorithm to find an optimal clique-coloring in circular-arc graphs or not. In this paper we present a linear-timealgorithm of the optimal clique-coloring in circular-arc graphs.
A well-known result about satisfiability theory is that the 2-SAT problem can be solved in lineartime, despite the N P-hardness of the 3-SAT problem. In the quantum 2-SAT problem, we are given a family of 2-qubit pro...
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A well-known result about satisfiability theory is that the 2-SAT problem can be solved in lineartime, despite the N P-hardness of the 3-SAT problem. In the quantum 2-SAT problem, we are given a family of 2-qubit projectors pi(ij) on a system of n qubits, and the task is to decide whether the Hamiltonian H = Sigma pi(ij) has a 0-eigenvalue, or all eigenvalues are greater than 1/n(alpha) for some alpha = O(1). The problem is not only a natural extension of the classical 2-SAT problem to the quantum case, but is also equivalent to the problem of finding a ground state of 2-local frustration-free Hamiltonians of spin 1/2, a well-studied model believed to capture certain key properties in modern condensed matter physics. Bravyi has shown that the quantum 2-SAT problem has a deterministic algorithm of complexity O(n(4)) in the algebraic model of computation where every arithmetic operation on complex numbers can be performed in unit time, and n is the number of variables. In this paper we give a deterministic algorithm in the algebraic model with running time O(n + m), where m is the number of local projectors, therefore achieving the best possible complexity in that model. We also show that if in the input every number has a constant size representation then the bit complexity of our algorithm is O((n+m)M(n)), where M(n) denotes the complexity of multiplying two n-bit integers.
The median of a set of vertices P of a graph G is the set of all vertices x of G minimizing the sum of distances from x to all vertices of P. In this paper, we present a linear time algorithm to compute medians in med...
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The median of a set of vertices P of a graph G is the set of all vertices x of G minimizing the sum of distances from x to all vertices of P. In this paper, we present a linear time algorithm to compute medians in median graphs. We also present a linear time algorithm to compute medians in the associated L-1-cube complexes. Our algorithm is based on the majority rule characterization of medians in median graphs and on a fast computation of parallelism classes of edges (0-classes) via Lexicographic Breadth First Search (LexBFS). We show that any LexBFS ordering of the vertices of a median graph satisfies the following fellow traveler property: the parents of any two adjacent vertices are also adjacent. Using the fast computation of the 0-classes, we also compute the Wiener index (total distance) in lineartime and the distance matrix in optimal quadratic time. (C)& nbsp;2022 Elsevier Inc. All rights reserved.
The Maximum Induced Matching ( MIM) Problem asks for a largest set of pairwise vertex- disjoint edges in a graph which are pairwise of distance at least two. It is well- known that the MIM problem is NP- complete even...
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The Maximum Induced Matching ( MIM) Problem asks for a largest set of pairwise vertex- disjoint edges in a graph which are pairwise of distance at least two. It is well- known that the MIM problem is NP- complete even on particular bipartite graphs and on line graphs. On the other hand, it is solvable in polynomial time for various classes of graphs ( such as chordal, weakly chordal, interval, circular- arc graphs and others) since the MIM problem on graph G corresponds to the Maximum Independent Set problem on the square G* = L( G) 2 of the line graph L( G) of G, and in some cases, G* is in the same graph class;for example, for chordal graphs G, G* is chordal. The construction of G*, however, requires O( m2) time, where m is the number of edges in G. Is has been an open problem whether there is a linear- timealgorithm for the MIM problem on chordal graphs. We give such an algorithm which is based on perfect elimination order and LexBFS.
Simchi-Levi (Naval Res. Logist. 41 (1994) 579-585) proved that the famous bin packing algorithms FF and BF have an absolute worst-case ratio of no more than 7/4, and FFD and BFD have an absolute worst-case ratio of 3/...
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Simchi-Levi (Naval Res. Logist. 41 (1994) 579-585) proved that the famous bin packing algorithms FF and BF have an absolute worst-case ratio of no more than 7/4, and FFD and BFD have an absolute worst-case ratio of 3/2, respectively. These algorithms run in time O(n log n). In this paper, we provide a lineartime constant space (number of bins kept during the execution of the algorithm is constant) off-line approximation algorithms with absolute worst-case ratio 3/2. This result is best possible unless P = NP. Furthermore, we present a lineartime constant space on-line algorithm and prove that the absolute worst-case ratio is 7/4. (C) 2000 Elsevier Science B.V. All rights reserved.
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