An Approximation Algorithm for Shortest Descending Paths

dc.creatorAhmed, Mustaq
dc.creatorLubiw, Anna
dc.date2007-05-09
dc.date.accessioned2026-07-07T08:00:34Z
dc.date.available2026-07-07T08:00:34Z
dc.descriptionA path from s to t on a polyhedral terrain is descending if the height of a point p never increases while we move p along the path from s to t. No efficient algorithm is known to find a shortest descending path (SDP) from s to t in a polyhedral terrain. We give a simple approximation algorithm that solves the SDP problem on general terrains. Our algorithm discretizes the terrain with O(n^2 X / e) Steiner points so that after an O(n^2 X / e * log(n X /e))-time preprocessing phase for a given vertex s, we can determine a (1+e)-approximate SDP from s to any point v in O(n) time if v is either a vertex of the terrain or a Steiner point, and in O(n X /e) time otherwise. Here n is the size of the terrain, and X is a parameter of the geometry of the terrain.
dc.description14 pages, 3 figures
dc.identifierhttps://arxiv.org/abs/0705.1364
dc.identifierhttp://arxiv.org/abs/0705.1364
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/128693
dc.subjectComputational Geometry
dc.subjectData Structures and Algorithms
dc.subjectF.2.2
dc.titleAn Approximation Algorithm for Shortest Descending Paths
dc.typetext

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