title: Sorting permutations by prefix and suffix rearrangements.
abstract: Some interesting combinatorial problems have been motivated by genome rearrangements, which are mutations that affect large portions of a genome. When we represent genomes as permutations, the goal is to transform a given permutation into the identity permutation with the minimum number of rearrangements. When they affect segments from the beginning (respectively end) of the permutation, they are called prefix (respectively suffix) rearrangements. This paper presents results for rearrangement problems that involve prefix and suffix versions of reversals and transpositions considering unsigned and signed permutations. We give 2-approximation and ([Formula: see text])-approximation algorithms for these problems, where [Formula: see text] is a constant divided by the number of breakpoints (pairs of consecutive elements that should not be consecutive in the identity permutation) in the input permutation. We also give bounds for the diameters concerning these problems and provide ways of improving the practical results of our algorithms.
authors.affiliation: † Institute of Computing, University of Campinas, Campinas, São Paulo, 13083-852, Brazil.
authors.forename: Carla Negri
authors.initials: CN
authors.lastname: Lintzmayer
authors.affiliation: ‡ Laboratoire des Sciences du Numérique de Nantes, UMR CNRS 6004, University of Nantes, 44322 Nantes Cedex 3, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Fertin
authors.affiliation: ‡ Laboratoire des Sciences du Numérique de Nantes, UMR CNRS 6004, University of Nantes, 44322 Nantes Cedex 3, France.
authors.forename: Zanoni
authors.initials: Z
authors.lastname: Dias
mesh_terms: D000465:Algorithms; D019295:Computational Biology / Q000379:methods*; D016678:Genome; D008957:Models, Genetic; D009154:Mutation
keywords: Permutations; approximation algorithms; diameter; prefix; reversals; sorting; suffix; transpositions