A SIMPLE OPTIMAL SYSTOLIC ALGORITHM FOR GENERATING PERMUTATIONS

1992 ◽  
Vol 02 (02n03) ◽  
pp. 231-239 ◽  
Author(s):  
SELIM G. AKL ◽  
IVAN STOJMENOVIĆ

We describe a simple parallel algorithm for generating all permutations of n elements. The algorithm is designed to be executed on a linear array of n processors, each having constant size memory and each being responsible for producing one element of a given permutation. There is a constant delay per permutation, leading to an O (n!) time solution. The algorithm is cost-optimal, assuming the time to output the permutations is counted.

1992 ◽  
Vol 02 (02n03) ◽  
pp. 241-248 ◽  
Author(s):  
HASSAN ELHAGE ◽  
IVAN STOJMENOVIĆ

A systolic algorithm is described for generating, in lexicographically ascending order, all combinations of m objects chosen from an arbitrary set of n elements. The algorithm is designed to be executed on a linear array of m processors, each having constant size memory (except processor m, which has O(n) memory), and each being responsible for producing one element of a given combination. There is a constant delay per combination, leading to an O (C(m, n)) time solution, where C(m, n) is the total number of combinations. The algorithm is cost-optimal (assuming the time to output the combinations is counted), and does not deal with very large integers.


1991 ◽  
Vol 01 (02) ◽  
pp. 143-148 ◽  
Author(s):  
SELIM G. AKL ◽  
THIBAULT DUBOUX ◽  
IVAN STOJMENOVIC

We present a cost-optimal parallel algorithm for generating variations of m elements out of {0, 1, …, n - 1} in lexicographic order. It uses a linear array of m processors, each having constant size memory and each being responsible for producing one part of a given variation. Binary and decimal counters are special cases of the algorithm, when n = 2 and n = 10, respectively. To our knowledge, the algorithm presented here is the first to be published with the property that the delay between any two variations generated is constant.


1996 ◽  
Vol 06 (01) ◽  
pp. 27-34 ◽  
Author(s):  
IVAN STOJMENOVIC

We present a cost-optimal parallel algorithm for generating n-ary reflected Gray codes, i.e. variations of m elements out of {0, 1,…, n–1} in a Gray code order. It uses a linear array of m processors, each having constant size memory and each being responsible for producing one part of a given variation. The algorithm is simple and uses a weaker model of computation than a recently published algorithm. In addition, it can be made adaptive (i.e. to run on a linear array with an arbitrary number of processors) and can be generalized to produce variations out of an arbitrary set of elements.


1998 ◽  
Vol 08 (04) ◽  
pp. 515-526 ◽  
Author(s):  
Thierry Lecroq ◽  
Jean-Frederic Myoupo ◽  
David Seme

This paper introduces a new linear systolic algorithm [10] for the sequence alignment problem [18]. It is made up of min(n, m) processors and computes the edit distance and the sequence alignment of two sequences Target and Source in time min(n, m) + 2.max(n, m), where n and m denote the lengths of Target and Source respectively. Its characteristics make it faster and more efficient than the previous linear array algorithm for the alignment search.


2004 ◽  
Vol 14 (01) ◽  
pp. 83-97
Author(s):  
JONG-CHUANG TSAY

A parenthesis string is a string of left and right parentheses. The string is well-formed when it consists of balanced pairs of left and right parentheses. This study presents a novel systolic algorithm for generating all the well-formed parenthesis strings in lexicographical order. The algorithm is cost-optimal and is run on a linear array of processors such that each well-formed parenthesis string can be generated in three time steps. The processor array is appropriate for VLSI implementation, since it has the features of modularity, regularity, and local connection.


1993 ◽  
Vol 03 (02) ◽  
pp. 157-164 ◽  
Author(s):  
P. THANGAVEL ◽  
V.P. MUTHUSWAMY

A simple parallel algorithm for generating N-ary reflected Gray codes is presented. The algorithm is derived from the pattern of N-ary reflected Gray codes. The algorithm runs on a linear processor array with a reconfigurable bus system. A reconfigurable bus system is a bus system whose configuration can be dynamically changed. Recently processor arrays with reconfigurable bus systems were used to solve many problems in constant time. There already exists experimental reconfigurable chips.


2001 ◽  
Vol 01 (04) ◽  
pp. 635-645 ◽  
Author(s):  
MARINA L. GAVRILOVA ◽  
MUHAMMAD H. ALSUWAIYEL

Given an n × n binary image of white and black pixels, we present two optimal algorithms for computing the distance transform and the nearest feature transform using the Euclidean metric. The first algorithm is a fast sequential algorithm that runs in linear time in the input size. The second is a parallel algorithm that runs in O(n2/p) time on a linear array of p processors, p, 1 ≤ p ≤ n.


1992 ◽  
Vol 25 (20) ◽  
pp. 29-35
Author(s):  
José L. Hueso ◽  
Gloria Martínez ◽  
Vicente Hernández

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