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 |
|---|---|
| Pages (from-to) | 438-449 |
| Number of pages | 12 |
| Journal | Theoretical Computer Science |
| Volume | 409 |
| Issue number | 3 |
| DOIs | |
| State | Published - 28 Dec 2008 |
Bibliographical note
Funding Information:The authors wish to thank the anonymous referees for their helpful comments. The first author was partly supported by ISF grant 35/05.
Funding
The authors wish to thank the anonymous referees for their helpful comments. The first author was partly supported by ISF grant 35/05.
| Funders | Funder number |
|---|---|
| Israel Science Foundation | 35/05 |
Keywords
- Longest common subsequence
- Matrices
- Non crossing matching
- Trees