TY - GEN
T1 - Fast algorithms for computing tree LCS
AU - Mozes, Shay
AU - Tsur, Dekel
AU - Weimann, Oren
AU - Ziv-Ukelson, Michal
PY - 2008/7/1
Y1 - 2008/7/1
N2 - The LCS of two rooted, ordered, and labeled trees F and G is the largest forest that can be obtained from both trees by deleting nodes. We present algorithms for computing tree LCS which exploit the sparsity inherent to the tree LCS problem. Assuming G is smaller than F, our first algorithm runs in time , where r is the number of pairs (v ∈ F, w ∈ G) such that v and w have the same label. Our second algorithm runs in time , where L is the size of the LCS of F and G. For this algorithm we present a novel three dimensional alignment graph. Our third algorithm is intended for the constrained variant of the problem in which only nodes with zero or one children can be deleted. For this case we obtain an time algorithm, where h = height(F) + height(G).
AB - The LCS of two rooted, ordered, and labeled trees F and G is the largest forest that can be obtained from both trees by deleting nodes. We present algorithms for computing tree LCS which exploit the sparsity inherent to the tree LCS problem. Assuming G is smaller than F, our first algorithm runs in time , where r is the number of pairs (v ∈ F, w ∈ G) such that v and w have the same label. Our second algorithm runs in time , where L is the size of the LCS of F and G. For this algorithm we present a novel three dimensional alignment graph. Our third algorithm is intended for the constrained variant of the problem in which only nodes with zero or one children can be deleted. For this case we obtain an time algorithm, where h = height(F) + height(G).
UR - https://www.scopus.com/pages/publications/45849145089
U2 - 10.1007/978-3-540-69068-9_22
DO - 10.1007/978-3-540-69068-9_22
M3 - Conference contribution
AN - SCOPUS:45849145089
SN - 3540690662
SN - 9783540690665
T3 - Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
SP - 230
EP - 243
BT - Combinatorial Pattern Matching - 19th Annual Symposium, CPM 2008, Proceedings
T2 - 19th Annual Symposium on Combinatorial Pattern Matching, CPM 2008
Y2 - 18 June 2008 through 20 June 2008
ER -