Research output: Contribution to journal › Article › peer-review
State complexity of cyclic shift. / Jirásková, Galina; Okhotin, Alexander.
In: RAIRO - Theoretical Informatics and Applications, Vol. 42, No. 2, 01.04.2008, p. 335-360.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - State complexity of cyclic shift
AU - Jirásková, Galina
AU - Okhotin, Alexander
PY - 2008/4/1
Y1 - 2008/4/1
N2 - The cyclic shift of a language , defined as =, is an operation known to preserve both regularity and context-freeness. Its descriptional complexity has been addressed in Maslov's pioneering paper on the state complexity of regular language operations [Soviet Math. Dokl. 11 (1970) 1373-1375], where a high lower bound for partial DFAs using a growing alphabet was given. We improve this result by using a fixed 4-letter alphabet, obtaining a lower bound (n-1)! 2, which shows that the state complexity of cyclic shift is for alphabets with at least 4 letters. For 2- and 3-letter alphabets, we prove state complexity. We also establish a tight 2n lower bound for the nondeterministic state complexity of this operation using a binary alphabet.
AB - The cyclic shift of a language , defined as =, is an operation known to preserve both regularity and context-freeness. Its descriptional complexity has been addressed in Maslov's pioneering paper on the state complexity of regular language operations [Soviet Math. Dokl. 11 (1970) 1373-1375], where a high lower bound for partial DFAs using a growing alphabet was given. We improve this result by using a fixed 4-letter alphabet, obtaining a lower bound (n-1)! 2, which shows that the state complexity of cyclic shift is for alphabets with at least 4 letters. For 2- and 3-letter alphabets, we prove state complexity. We also establish a tight 2n lower bound for the nondeterministic state complexity of this operation using a binary alphabet.
KW - Cyclic shift
KW - Descriptional complexity
KW - Finite automata
UR - http://www.scopus.com/inward/record.url?scp=41549087893&partnerID=8YFLogxK
U2 - 10.1051/ita:2007038
DO - 10.1051/ita:2007038
M3 - Article
AN - SCOPUS:41549087893
VL - 42
SP - 335
EP - 360
JO - RAIRO - Theoretical Informatics and Applications
JF - RAIRO - Theoretical Informatics and Applications
SN - 0988-3754
IS - 2
ER -
ID: 41141610