On Sorting of Signed Permutations by Prefix and Suffix Reversals and Transpositions

Author(s):  
Carla Negri Lintzmayer ◽  
Zanoni Dias
Keyword(s):  
2006 ◽  
Vol 306 (6) ◽  
pp. 552-563 ◽  
Author(s):  
Eric S. Egge

10.37236/8106 ◽  
2018 ◽  
Vol 25 (3) ◽  
Author(s):  
David Anderson

We introduce diagrams and essential sets for signed permutations, extending the analogous notions for ordinary permutations.  In particular, we show that the essential set provides a minimal list of rank conditions defining the Schubert variety or degeneracy locus corresponding to a signed permutation.  Our essential set is in bijection with the poset-theoretic version defined by Reiner, Woo, and Yong, and thus gives an explicit, diagrammatic method for computing the latter.


Author(s):  
Klairton Lima Brito ◽  
Andre Rodrigues Oliveira ◽  
Ulisses Dias ◽  
Zanoni Dias
Keyword(s):  

2006 ◽  
Vol 113 (7) ◽  
pp. 642 ◽  
Author(s):  
Valerio De Angelis
Keyword(s):  

2015 ◽  
Vol 68 ◽  
pp. 18-50 ◽  
Author(s):  
Sen-Peng Eu ◽  
Yuan-Hsun Lo ◽  
Tsai-Lien Wong

2017 ◽  
Vol 47 (2) ◽  
pp. 391-402
Author(s):  
Michael P. Allocca ◽  
Steven T. Dougherty ◽  
Jennifer F. Vasquez

2011 ◽  
Vol 21 (01) ◽  
pp. 87-100
Author(s):  
GREG ALOUPIS ◽  
PROSENJIT BOSE ◽  
ERIK D. DEMAINE ◽  
STEFAN LANGERMAN ◽  
HENK MEIJER ◽  
...  

Given a planar polygon (or chain) with a list of edges {e1, e2, e3, …, en-1, en}, we examine the effect of several operations that permute this edge list, resulting in the formation of a new polygon. The main operations that we consider are: reversals which involve inverting the order of a sublist, transpositions which involve interchanging subchains (sublists), and edge-swaps which are a special case and involve interchanging two consecutive edges. When each edge of the given polygon has also been assigned a direction we say that the polygon is signed. In this case any edge involved in a reversal changes direction. We show that a star-shaped polygon can be convexified using O(n2) edge-swaps, while maintaining simplicity, and that this is tight in the worst case. We show that determining whether a signed polygon P can be transformed to one that has rotational or mirror symmetry with P, using transpositions, takes Θ(n log n) time. We prove that the problem of deciding whether transpositions can modify a polygon to fit inside a rectangle is weakly NP-complete. Finally we give an O(n log n) time algorithm to compute the maximum endpoint distance for an oriented chain.


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