The Computer Journal Advance Access published online on June 22, 2007
The Computer Journal, doi:10.1093/comjnl/bxm022
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Some Generalizations Of a SimionSchmidt Bijection
LE2IUMR CNRS, Université de Bourgogne, B.P. 47 870, 21078 Dijon Cedex, France
* Correspondence author: vvajnov{at}u-bourgogne.fr
Received 16 June 2006; revised 20 January 2007
In 1985, Simion and Schmidt gave a constructive bijection
from the set of all length (n 1) binary strings having no two consecutive 1s to the set of all length n permutations avoiding all patterns in {123,132,213}. In this paper, we generalize
to an injective function from {0,1}n1 to the set Sn of all length n permutations and derive from it four bijections
: P
Q where P
{0,1}n1 and Q
Sn. The domains are sets of restricted binary strings and the codomains are sets of pattern-avoiding permutations. As a particular case we retrieve the original SimionSchmidt bijection. We also show that the bijections obtained are actually combinatorial isomorphisms, i.e. closeness-preserving bijections. Three of them have known Gray codes and generating algorithms for their domains and we present similar results for each corresponding codomain, under the appropriate combinatorial isomorphism.
Key Words: pattern-avoiding permutations Fibonacci and Lucas strings constructive bijections combinatorial isomorphisms Gray codes