Journal of applied mathematics & informatics
- 제26권3_4호
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- Pages.627-641
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- 2008
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- 2734-1194(pISSN)
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- 2234-8417(eISSN)
TIGHT UPPER BOUND ON THE EXPONENTS OF A CLASS OF TWO-COLORED DIGRAPHS
- Wang, Rong (Department of Mathematics, North University of China) ;
- Shao, Yanling (Department of Mathematics, North University of China) ;
- Gao, Yubin (Department of Mathematics, North University of China)
- 발행 : 2008.05.31
초록
A two-colored digraph D is primitive if there exist nonnegative integers hand k with h + k > 0 such that for each pair (i, j) of vertices there exists an (h, k)-walk in D from i to j. The exponent of the primitive two-colored digraph D is the minimum value of h + k taken over all such hand k. In this paper, we give the tight upper bound on the exponents of a class of primitive two-colored digraphs with (s + 1) n-cycles and one (n - 1)-cycle, and the characterizations of the extremal two-colored digraphs.