Fast Recognition of Pushdown Automaton Context-free Languages
نویسنده
چکیده
We prove: (1) every language accepted by a two-way nondeterministic pushdown automaton can be recognized on a random access machine in O(n3/log n) time; (2) every language accepted by a loop-free two-way nondeterministic pushdown automaton can be recognized in O(n3/log 2 n) time; (3) every context-free language can be recognized onqine in O(n3/log z n) time. We improve the results of Aho, Hopcroft, and Ullman (Inform. Contr. 13, 1968, 186-206), Rytter (Inform. Process. Lett. 16, 1983, 127-129), and Graham, Harrison, and Ruzzo (ACM Trans. Programm. Lang. Systems 2, No. 3~ 1980, 415462). © 1985 Academic Press, Inc.
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