Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

On finding lowest common ancestors

Journal Article · · SIAM J. Comput.; (United States)
DOI:https://doi.org/10.1137/0217079· OSTI ID:6450109
The authors consider the following problem. Suppose a rooted tree T is available for preprocessing. Answer on-line queries requesting the lowest common ancestor for any pair of vertices in T. They present a linear time and space preprocessing algorithm that enables us to answer each query in O(1) time, as in previous algorithms. Our algorithm has the advantage of being simple and easily parallelizable. The resulting parallel preprocessing algorithm runs in logarithmic time using an optimal number of processors on an EREW PRAM. Each query is then answered in O(1) time using a single processor.
Research Organization:
T.J. Watson Research Center, IBM Research Div., Yorktown Heights, NY (US)
OSTI ID:
6450109
Journal Information:
SIAM J. Comput.; (United States), Journal Name: SIAM J. Comput.; (United States) Vol. 17:6; ISSN SMJCA
Country of Publication:
United States
Language:
English

Similar Records

Finding lowest common ancestors in parallel
Journal Article · Fri Aug 01 00:00:00 EDT 1986 · IEEE Trans. Comput.; (United States) · OSTI ID:5364487

Parallel algorithm for finding a blocking flow in an acyclic network
Technical Report · Sat Oct 01 00:00:00 EDT 1988 · OSTI ID:7083935

Efficient parallel algorithms for (5+1)-coloring and maximal independent set problems
Technical Report · Wed Dec 31 23:00:00 EST 1986 · OSTI ID:6487978