Title
Indexing ordered trees for (nonlinear) tree pattern matching by pushdown automata.
Abstract
Trees are one of the fundamental data structures used in Computer Science. We present a new kind of acyclic pushdown automata, the tree pattern pushdown automaton and the nonlinear tree pattern pushdown automaton, constructed for an ordered tree. These automata accept all tree patterns and nonlinear tree patterns, respectively, which match the tree and represent a full index of the tree for such patterns. Given a tree with n nodes, the numbers of these distinct tree patterns and nonlinear tree patterns can be at most 2(n-1) + n and at most (2 + v)(n-1) + 2, respectively, where v is the maximal number of nonlinear variables allowed in nonlinear tree patterns. The total sizes of nondeterministic versions of the two pushdown automata are O(n) and O(n(2)), respectively. We discuss the time complexities and show timings of our implementations using the bit-parallelism technique. The timings show that for a given tree the running time is linear to the size of the input pattern.
Year
DOI
Venue
2012
10.2298/CSIS111220024T
COMPUTER SCIENCE AND INFORMATION SYSTEMS
Keywords
Field
DocType
Tree pattern matching,nonlinear tree pattern matching,indexing trees,pushdown automata
Discrete mathematics,Data mining,Range tree,AVL tree,Computer science,K-ary tree,Algorithm,Tree structure,Segment tree,Fractal tree index,Search tree,Interval tree
Journal
Volume
Issue
ISSN
9
SP3
1820-0214
Citations 
PageRank 
References 
0
0.34
10
Authors
3
Name
Order
Citations
PageRank
Jan Travnicek111.72
Jan Janousek2234.80
Borivoj Melichar37216.63