Title
A Hamilton Path for the Sigma-Tau Problem.
Abstract
Nijenhuis and Wilf asked the following question in their Combinatorial Algorithms textbook from 1975: Can the permutations of {1, 2,...,n} be ordered so that each permutation is transformed into the next by applying either the operation σ, a rotation to the left, or τ, a transposition of the first two symbols? Knuth rated the challenge of finding a cyclic solution for odd n (cycles do not exist for even n > 2) at 48/50 in The Art of Computer Programming, which makes it Volume 4's hardest open problem since the 'middle levels' problem was solved by Mütze. In this paper we solve the 40 year-old question by Nijenhuis and Wilf, by providing a simple successor rule to generate each successive permutation. We also present insights into how our solution can be modified to find a Hamilton cycle for odd n.
Year
DOI
Venue
2018
10.5555/3174304.3175307
SODA '18: Symposium on Discrete Algorithms New Orleans Louisiana January, 2018
Field
DocType
ISBN
Generating function,Discrete mathematics,Combinatorics,Open problem,Computer science,Successor cardinal,Hamiltonian path,Combinatorial algorithms,Permutation,Sigma,Computer programming
Conference
978-1-61197-503-1
Citations 
PageRank 
References 
0
0.34
1
Authors
2
Name
Order
Citations
PageRank
Joe Sawada1669.11
Aaron Williams213920.42