A polynomial time algorithm for finding an approximate shortest path amid weighted regions
نویسندگان
چکیده
We devise a polynomial-time approximation scheme for the classical geometric problem of finding an ǫ-short path amid weighted regions. In this problem, a triangulated region P comprising of n triangles, a positive weight associated with each triangle, and two points s and t that belong to P are given as the input. The objective is to find a path whose cost is at most (1+ ǫ)OPT where OPT is the cost of an optimal path between s and t. Our algorithm initiates a discretized-Dijkstra wavefront from source s and progresses the wavefront till it strikes t. This result is about a cubic factor (in n) improvement over the Mitchell and Papadimitriou ’91 result [8], which is the only known polynomial time algorithm for this problem to date.
منابع مشابه
Approximate Shortest Path through a Weighted Planar Subdivision
This paper presents an approximation algorithm for finding a shortest path between two points s and t in a weighted planar subdivision P . Each face f of P is associated with a weight wf , and the cost of travel along a line segment on f is wf multiplied by the Euclidean norm of that line segment. The cost of a path which traverses across several faces of the subdivision is the sum of the costs...
متن کاملApproximate Euclidean shortest paths amid convex obstacles
We develop algorithms and data structures for the approximate Euclidean shortest path problem amid a set P of k convex obstacles in R and R, with a total of n faces. The running time of our algorithms is linear in n, and the size and query time of our data structure are independent of n. We follow a “core-set” based approach, i.e., we quickly compute a small sketch Q of P whose size is independ...
متن کاملNavigating Weighted Regions with Scattered Skinny Tetrahedra
We propose an algorithm for finding a (1 + ε)-approximate shortest path through a weighted 3D simplicial complex T . The weights are integers from the range [1,W ] and the vertices have integral coordinates. Let N be the largest vertex coordinate magnitude, and let n be the number of tetrahedra in T . Let ρ be some arbitrary constant. Let κ be the size of the largest connected component of tetr...
متن کاملOptimum Routing in the Urban Transportation Network by Integrating Genetic Meta-heuristic (GA) and Tabu Search (Ts) Algorithms
Urban transportation is one of the most important issues of urban life especially in big cities. Urban development, and subsequently the increase of routes and communications, make the role of transportation science more pronounced. The shortest path problem in a network is one of the most basic network analysis issues. In fact, finding answers to this question is necessity for higher level ana...
متن کاملApproximate shortest paths in moderately anisotropic regions
We want to find an approximate shortest path for a point robot moving in a planar subdivision. Each face of the subdivision is associated with a convex distance function that has the following property: its unit disk contains a unit Euclidean disk, and is contained in a Euclidean disk with radius ρ. Obstacles are allowed, so there can be regions that the robot is not allowed to enter. We give a...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- CoRR
دوره abs/1501.00340 شماره
صفحات -
تاریخ انتشار 2015