Parallel time O(log n) acceptance of deterministic cfls on an exclusive-write P-RAM

Journal Article · Wed Jun 01 00:00:00 EDT 1988 · SIAM J. Comput.; (United States)

DOI:https://doi.org/10.1137/0217027· OSTI ID:6987765

Klein, P N; Reif, J H

The authors given an algorithm for accepting a deterministic context-free language on the P-RAM, and exclusive-write, concurrent-read model of parallel computation. Whereas on inputs of length n, a deterministic push-down automaton will use time linear in n, the authors' algorithm runs in time O(log n) on n/sup 3/ processors. The algorithm is easily generalized to permit parallel simulation of any deterministic auxiliary pushdown automaton that uses space s(n) greater than or equal to log n and time 2/sup O(s(n))/. The simulation runs in time O(s(n)) on 2/sup O(s(n))/ processors, and is nearly optimal, since the authors observe that any language accepted by a P-RAM in time T(n) is accepted by a deterministic auxiliary pushdown automaton in space T(n) and time 2/sup O(T(n)/2/sup )/.

• Research Organization: Lab. for Computer Science, Massachusetts Institute of Technology, Cambridge, MA (US)
• OSTI ID: 6987765
• Journal Information: SIAM J. Comput.; (United States), Vol. 17:3
• Country of Publication: United States
• Language: English

Related Subjects

99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
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PROGRAMMING LANGUAGES
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990210* - Supercomputers- (1987-1989)