Algorithms for string searching
ACM SIGIR Forum
A lower bound for parallel string matching
STOC '91 Proceedings of the twenty-third annual ACM symposium on Theory of computing
String matching with simple devices
Information Processing Letters
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New techniques for obtaining lower bounds on string-matching problems are developed and we prove the following new results. String-matching cannot be performed by a three-head one-way deterministic finite automaton. This answers the $k=3$ case of the open question, due to Galil and Seiferas [GS], whether a $k$-head one-way deterministic finite automaton can perform string-matching. String-matching by a k-head two-way DFA with k-1 heads blind (can only see two end symbols) is studied, tight upper and lower bounds are provided. Probabilistically moving a string on one tape (requiring $n^{2}$ time) is harder than probabilistically matching two strings on 1 tape. Notice that this is not true for deterministic or even nondeterministic TMs. This is the first result showing that checking is easier than generating.