Abstract
The Longest Common Subsequence (LCS) is a well studied problem, having a wide range of implementations. Its motivation is in comparing strings. It has long been of interest to devise a similar measure for comparing higher dimensional objects, and more complex structures. In this paper we study the Longest Common Substructure of two matrices and show that this problem is N P-hard. We also study the Longest Common Subforest problem for multiple trees including a constrained version, as well. We show N P-hardness for k > 2 unordered trees in the constrained LCS. We also give polynomial time algorithms for ordered trees and prove a lower bound for any decomposition strategy for k trees.
Original language | English |
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Pages (from-to) | 438-449 |
Number of pages | 12 |
Journal | Theoretical Computer Science |
Volume | 409 |
Issue number | 3 |
DOIs | |
State | Published - 28 Dec 2008 |
Keywords
- Longest common subsequence
- Matrices
- Non crossing matching
- Trees
ASJC Scopus subject areas
- Theoretical Computer Science
- General Computer Science