Search results for "Rencontres numbers"

showing 2 items of 2 documents

Gray code for derangements

2004

AbstractWe give a Gray code and constant average time generating algorithm for derangements, i.e., permutations with no fixed points. In our Gray code, each derangement is transformed into its successor either via one or two transpositions or a rotation of three elements. We generalize these results to permutations with number of fixed points bounded between two constants.

021103 operations researchMathematics::CombinatoricsRestricted permutationsApplied Mathematics0211 other engineering and technologiesGenerating algorithms0102 computer and information sciences02 engineering and technologyFixed pointGray codes01 natural sciencesCombinatoricsGray codePermutationDerangement010201 computation theory & mathematicsBounded function[MATH.MATH-CO]Mathematics [math]/Combinatorics [math.CO]Discrete Mathematics and CombinatoricsConstant (mathematics)Rotation (mathematics)Rencontres numbersComputingMilieux_MISCELLANEOUSMathematicsDiscrete Applied Mathematics
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Generating restricted classes of involutions, Bell and Stirling permutations

2010

AbstractWe present a recursive generating algorithm for unrestricted permutations which is based on both the decomposition of a permutation as a product of transpositions and that as a union of disjoint cycles. It generates permutations at each recursive step and slight modifications of it produce generating algorithms for Bell permutations and involutions. Further refinements yield algorithms for these classes of permutations subject to additional restrictions: a given number of cycles or/and fixed points. We obtain, as particular cases, generating algorithms for permutations counted by the Stirling numbers of the first and second kind, even permutations, fixed-point-free involutions and d…

Discrete mathematicsGolomb–Dickman constantMathematics::CombinatoricsStirling numbers of the first kindParity of a permutationTheoretical Computer ScienceCombinatoricsDerangementPermutationComputational Theory and MathematicsRandom permutation statisticsDiscrete Mathematics and CombinatoricsStirling numberGeometry and TopologyRencontres numbersMathematicsMathematicsofComputing_DISCRETEMATHEMATICSEuropean Journal of Combinatorics
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