Showing papers in "Journal of Algorithms in 1991"

TL;DR: Using a variation of the interpretability concept, it is shown that all graph properties definable in monadic second-order logic with quantification over vertex and edge sets can be decided in linear time for classes of graphs of fixed bounded treewidth given a tree-decomposition.

TL;DR: The marking algorithm is developed, a randomized on-line algorithm for the paging problem, which it is proved that its expected cost on any sequence of requests is within a factor of 2Hk of optimum.

TL;DR: A new proof of the result, due to A. LaPaugh, that a graph may be optimally “searched” without clearing any edge twice is given.

TL;DR: A new structure called a “stable partition” is defined, which generalizes the notion of a complete stable matching, and it is proved that every instance of the stable roommates problem has at least one such structure.

TL;DR: The problem of maintaining on-line a solution to the All Pairs Shortest Paths Problem in a directed graph G = (V,E) where edges may be dynamically inserted or have their cost decreased is considered and a new data structure is introduced which is able to answer queries concerning the length of the shortest path between any two vertices in constant time.

TL;DR: In this article, the authors consider the problem of finding k points of a set S that form a small set under some given measure, and present efficient algorithms for several natural measures including the diameter and variance.

TL;DR: A probabilistic algorithm with execution time O(n log2 n + n log n∥log p∥), which for a graph G on n vertices and a real number p > 0 either finds a tree-decomposition of width ≤ 6w or answers that the tree-width of G is ≥ w; this second answer may be wrong but with probability at most p.

TL;DR: This paper presents algorithms for several natural measures, including the diameter ( set measure ), the area, perimeter, or diagonal of the smallest enclosing axes-parallel rectangle ( rectangular measure), the side length of the largest enclosing axiomatic square ( square measure), and the radius of the biggest enclosing circle ( circular measure).

TL;DR: This paper shows that the optimal K-level quantizer problem can be solved in O(KN) time, by a better understanding of the objective function in this particular non-linear programming problem and the use of Aggarwal et al.'s matrix-searching technique.

TL;DR: An efficient probabilistic algorithm for a Monte-Carlo approximation to the Hough transform that requires substantially less computation and storage than the standard Houghtransform when applied to patterns that are easily recognized by humans.

TL;DR: The authors' algorithm for computing the complete visibility polygon of P from a convex set inside P leads to efficient algorithms for the following problems: Given a polygon Q of m vertices inside another polygon P of n vertices, construct a minimum nested convex polygon K between P and Q in O((n + m)log k) time, where k is the number of vertices.

TL;DR: A result of independent interest is a parallel hashing technique that enables drastic reduction of space requirements for the price of using randomness in the parallel sorting algorithm and for some parallel string matching algorithms.

TL;DR: An efficient algorithm for Waterman's problem, an on-line two-dimensional dynamic programming problem that is used for the prediction of RNA secondary structure, and an O(n + h log min{h, n2h}) time algorithm for the sparse convex case, where h is the number of possible base pairs in the RNA structure.

TL;DR: The main result of this paper is that the set of minimal braids is co-NP-complete.

TL;DR: An algorithm which reduces integer lattices in the two-dimensional case and finds a basis of a lattice consisting of its two successive minima and generalizes the worst-case input configuration of the centered Euclidean algorithm to dimension two is exhibited.

TL;DR: Tight bounds are given on the average complexity of various problems of a bidirectional ring of n processors, where processors are anonymous, i.e., are indistinguishable.

TL;DR: It is proved that for each n there is a graph G n such that the chromatic number of G n is at most n e, but the probability that A(G n, p) (1 − ϑ)n log 2 n for a randomly chosen ordering p is O ( n − Δ ).

TL;DR: A probabilistic analysis of the dual bin packing problem is carried out under the assumption that the items are drawn independently from the uniform distribution on [0, 1] and the connection between this problem and the classical binpacking problem as well as to renewal theory is revealed.

TL;DR: This paper gives the first NC algorithm for recognizing the consecutive 1's property for rows of a (0, 1)-matrix, and shows that the maximum matching problem for arbitrary convex bipartite graphs can be solved within the same complexity bounds.

TL;DR: A parallel algorithm for recognizing series parallel graphs and constructing decomposition trees and takes O(log2 n + log m) time with O(n + m) processors, where n (m) is the number of vertices (edges) in the graph.

TL;DR: It is shown that, assuming the generalized Riemann hypothesis, there exists a deterministic polynomial time algorithm, which on input of a rational prime p and a monic integral polynometric f computes all the irreducible factors of f mod p in F p.

TL;DR: In this article, the authors developed techniques based on X-ray probing to determine convex n-gons in 7n + 7 half-plane probes and proved linear lower bounds for determination and verification.

TL;DR: It is shown that the previously known algorithm BALANCE2 has competitiveness constant not better than 6, and another algorithm whose competitiveness constant is 4 is presented.

TL;DR: It is shown that any graph G can be embedded with unit congestion in a hypercube of dimension n ≥ max{6⌈log|V(G)|⌉, deg( G )}, but it is NP-complete to determine whether G is congestion-1 embeddable in a given hypercube, even if the source graph is connected.

TL;DR: This paper presents an O ( n log n ) algorithm for finding a minimum 3-cut in planar graphs and improves the best previously known algorithm for the problem by an O( n logn) factor.

TL;DR: It is shown that the average number of swaps required to construct a heap on n keys by Williams’ method of repeated insertion is (! + o(1))n, where the constant ! is about 1.3.

TL;DR: This work presents a parallel algorithm for this problem, which runs in polylog parallel time and uses O ( n 3 ) processors on a PRAM and the major tool it uses is computing a minimum-weight branching with zero-one weights.

TL;DR: The paper points out that the CS interacts with the access model to produce some remarkable synergistic effects that make it possible to use very effective “truncated versions of the CS, which have very modest space requirements.

TL;DR: A parallel algorithm to recognize parity graphs and a parallel algorithm for finding the size of a maximum clique which runs in O(log2 n) time with n3log 2 n processors are presented.