Average case analysis of algorithms for the maximum subarray problem

Type of content
Theses / Dissertations
Publisher's DOI/URI
Thesis discipline
Computer Science
Degree name
Master of Science
Publisher
University of Canterbury. Computer Science and Software Engineering
Journal Title
Journal ISSN
Volume Title
Language
Date
2007
Authors
Bashar, Mohammad Ehsanul
Abstract

Maximum Subarray Problem (MSP) is to find the consecutive array portion that maximizes the sum of array elements in it. The goal is to locate the most useful and informative array segment that associates two parameters involved in data in a 2D array. It's an efficient data mining method which gives us an accurate pattern or trend of data with respect to some associated parameters. Distance Matrix Multiplication (DMM) is at the core of MSP. Also DMM and MSP have the worst-case complexity of the same order. So if we improve the algorithm for DMM that would also trigger the improvement of MSP. The complexity of Conventional DMM is O(n³). In the average case, All Pairs Shortest Path (APSP) Problem can be modified as a fast engine for DMM and can be solved in O(n² log n) expected time. Using this result, MSP can be solved in O(n² log² n) expected time. MSP can be extended to K-MSP. To incorporate DMM into K-MSP, DMM needs to be extended to K-DMM as well. In this research we show how DMM can be extended to K-DMM using K-Tuple Approach to solve K-MSP in O(Kn² log² n log K) time complexity when K ≤ n/log n. We also present Tournament Approach which solves K-MSP in O(n² log² n + Kn²) time complexity and outperforms the K-Tuple

Description
Citation
Keywords
Maximum Subarray Problem, Distance Matrix Multiplication, All Pairs Shortest Path Problem, Shortest Path, Expected Time, Average Time, Average Case Analysis, Binary Heap, Prefix Sum, Directed Acyclic Graph, X + Y Problem, Binary Tournament Tree, Solution Set, MSP, K-MSP, DMM, K-DMM, APSP, K-Tuple
Ngā upoko tukutuku/Māori subject headings
ANZSRC fields of research
Rights
Copyright Mohammad Ehsanul Bashar