Long tours and short superstrings

Author

Kosaraju, S. Rao ; Park, James K. ; Stein, Clifford

Author_Institution

Dept. of Comput. Sci., Johns Hopkins Univ., Baltimore, MD, USA

fYear

1994

fDate

20-22 Nov 1994

Firstpage

166

Lastpage

177

Abstract

This paper considers weight-maximizing variants of the classical symmetric and asymmetric traveling-salesman problems. Like their weight-minimizing counterparts, these variants are MAX SNP-hard. We present the first nontrivial approximation algorithms for these problems. Our algorithm for directed graphs finds a tour whose weight is at least 38/63≈0.603 times the weight of a maximum-weight tour, and our algorithm for undirected graphs finds a tour whose weight is at least 5/7≈0.714 times optimal. These bounds compare favorably with the 1/2 and 2/3 bounds that can be obtained for undirected and directed graphs, respectively, by simply deleting the minimum-weight edge from each cycle of a maximum-weight cycle cover. Our algorithm for directed graphs can be used to improve several recent approximation results for the shortest-superstring problem

Keywords

computational complexity; computational geometry; directed graphs; operations research; MAX SNP-hard; directed graphs; long tours; nontrivial approximation algorithms; short superstrings; shortest-superstring problem; traveling-salesman problems; undirected graphs; weight-maximizing variants; weight-minimizing counterparts; Algorithm design and analysis; Approximation algorithms; Computer science; DNA; Data compression; Educational institutions; NP-hard problem; Polynomials; Upper bound;

fLanguage

English

Publisher

ieee

Conference_Titel

Foundations of Computer Science, 1994 Proceedings., 35th Annual Symposium on

Conference_Location

Santa Fe, NM

Print_ISBN

0-8186-6580-7

Type

conf

DOI

10.1109/SFCS.1994.365696

Filename

365696