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Priority Queue Sorting and Labeled Trees
A.M. Hamel
Department of Physics and Computer Science, Wilfrid Laurier University, Waterloo Ontario, N2L 3C5, Canada
ahamel@wlu.ca
Annals of Combinatorics 7 (1) p.49-54 March, 2003
AMS Subject Classification: 68R05
Abstract:
We construct a bijection between labeled trees and allowable pairs of permutations sorted by a priority queue. These are also the pairs of permutations that avoid the pattern pairs (12,21) and (321,132). Our bijection has the additional property that it maps leaves in the tree to descents in the output permutation in the allowable pair and, more generally, preserves the edge-deletion distribution of the tree.
Keywords: priority queue, allowable pairs, labeled trees

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