TY - GEN
T1 - Average case analysis for tree labelling schemes
AU - Kao, Ming-Yang
AU - Li, Xiang Yang
AU - Wang, Weizhao
N1 - Funding Information:
First author’s research supported in part by NSF Grant IIS-0121491.
PY - 2005
Y1 - 2005
N2 - We study how to label the vertices of a tree in such a way that we can decide the distance of two vertices in the tree given only their labels. For trees, Gavoille et al. [7] proved that for any such distance labelling scheme, the maximum label length is at least 1/8 log2 n - O(log n) bits. They also gave a separator-based labelling scheme that has the optimal label length Θ(log n · log(Hn(T))), where Hn(T) is the height of the tree. In this paper, we present two new distance labelling schemes that not only achieve the optimal label length Θ (log n · log(Hn(T))), but also have a much smaller expected label length under certain tree distributions. With these new schemes, we also can efficiently find the least common ancestor of any two vertices based on their labels only.
AB - We study how to label the vertices of a tree in such a way that we can decide the distance of two vertices in the tree given only their labels. For trees, Gavoille et al. [7] proved that for any such distance labelling scheme, the maximum label length is at least 1/8 log2 n - O(log n) bits. They also gave a separator-based labelling scheme that has the optimal label length Θ(log n · log(Hn(T))), where Hn(T) is the height of the tree. In this paper, we present two new distance labelling schemes that not only achieve the optimal label length Θ (log n · log(Hn(T))), but also have a much smaller expected label length under certain tree distributions. With these new schemes, we also can efficiently find the least common ancestor of any two vertices based on their labels only.
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U2 - 10.1007/11602613_15
DO - 10.1007/11602613_15
M3 - Conference contribution
AN - SCOPUS:33744960547
SN - 3540309357
SN - 9783540309352
T3 - Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
SP - 136
EP - 145
BT - Algorithms and Computation - 16th International Symposium, ISAAC 2005, Proceedings
T2 - 16th International Symposium on Algorithms and Computation, ISAAC 2005
Y2 - 19 December 2005 through 21 December 2005
ER -