In 1985, Simion and Schmidt gave a constructive bijection phi 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 {123,132,21...
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In 1985, Simion and Schmidt gave a constructive bijection phi 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 p to an injective function from {0,1}(n-1) to the set S. of all length n permutations and derive from it four bijections phi : P -> Q where P subset of{0,1}(n-1) and Q subset of S-n. 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 Simion-Schmidt 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.
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