Abstract
We study the problem of finding shortest paths in the plane among h convex obstacles, where the path is allowed to pass through (violate) up to k obstacles, for \(k \le h\). Equivalently, the problem is to find shortest paths that become obstacle-free if k obstacles are removed from the input. Given a fixed source point s, we show how to construct a map, called a shortest k-path map, so that all destinations in the same region of the map have the same combinatorial shortest path passing through at most k obstacles. We prove a tight bound of \(\varTheta (kn)\) on the size of this map, and show that it can be computed in \(O(k^2n \log n)\) time, where n is the total number of obstacle vertices.
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Notes
The garage metaphor is also used in the context of finding homotopically different paths in [12], but the properties and technical details of our k-garage are quite different.
References
Abellanas, M., García, A., Hurtado, F., Tejel, J., Urrutia, J.: Augmenting the connectivity of geometric graphs. Comput. Geom. 40(3), 220–230 (2008)
Agarwal, P.K., Kumar, N., Sintos, S., Suri, S.: Computing shortest paths in the plane with removable obstacles. In: 16th Scandinavian Symposium and Workshops on Algorithm Theory (SWAT 2018), vol. 101, pp. 5:1–5:15 (2018)
Ahuja, R.K., Magnanti, T.L., Orlin, J.B.: Network Flows: Theory, Algorithms, and Applications. Prentice Hall, Upper Saddle River (1993)
Asano, T.: An efficient algorithm for finding the visibility polygon for a polygonal region with holes. IEICE Trans. (1976–1990) 68(9), 557–559 (1985)
Asano, T., Asano, T., Guibas, L., Hershberger, J., Imai, H.: Visibility of disjoint polygons. Algorithmica 1(1–4), 49–63 (1986)
Bandyapadhyaya, S., Kumar, N., Suri, S., Varadrajan, K.: Improved approximation bounds for the minimum constraint removal problem. In: 21st International Conference on Approximation Algorithms for Combinatorial Optimization Problems (APPROX) (2018)
Carufel, J.L.D., Grimm, C., Maheshwari, A., Smid, M.: Minimizing the continuous diameter when augmenting paths and cycles with shortcuts. In: 15th Scandinavian Symposium and Workshops on Algorithm Theory, pp. 27:1–27:14 (2016)
Chan, T.M.: Low-dimensional linear programming with violations. SIAM J. Comput. 34(4), 879–893 (2005)
Chen, D.Z., Wang, H.: Computing shortest paths among curved obstacles in the plane. ACM Trans. Algorithms 11(4), 26:1–26:46 (2015)
Edelsbrunner, H., Guibas, L.J., Stolfi, J.: Optimal point location in a monotone subdivision. SIAM J. Comput. 15(2), 317–340 (1986)
Eiben, E., Gemmell, J., Kanj, I., Youngdahl, A.: Improved results for minimum constraint removal. In: Proceedings of AAAI, AAAI press (2018)
Eriksson-Bique, S., Hershberger, J., Polishchuk, V., Speckmann, B., Suri, S., Talvitie, T., Verbeek, K., Yıldız, H.: Geometric \(k\) shortest paths. In: Proceedings of the Twenty-Sixth Annual ACM-SIAM Symposium on Discrete Algorithms, pp. 1616–1625 (2015)
Farshi, M., Giannopoulos, P., Gudmundsson, J.: Improving the stretch factor of a geometric network by edge augmentation. SIAM J. Comput. 38(1), 226–240 (2008)
Ghosh, S.K., Mount, D.M.: An output-sensitive algorithm for computing visibility graphs. SIAM J. Comput. 20(5), 888–910 (1991)
Guibas, L., Hershberger, J., Leven, D., Sharir, M., Tarjan, R.E.: Linear-time algorithms for visibility and shortest path problems inside triangulated simple polygons. Algorithmica 2(1–4), 209–233 (1987)
Har-Peled, S., Koltun, V.: Separability with outliers. 16th International Symposium on Algorithms and Computation, pp. 28–39 (2005)
Hershberger, J., Kumar, N., Suri, S.: Shortest paths in the plane with obstacle violations. In: 25th Annual European Symposium on Algorithms (ESA 2017), vol. 87, pp. 49:1–49:14 (2017)
Hershberger, J., Snoeyink, J.: Computing minimum length paths of a given homotopy class. Comput. Geom. 4(2), 63–97 (1994)
Hershberger, J., Suri, S.: An optimal algorithm for Euclidean shortest paths in the plane. SIAM J. Comput. 28(6), 2215–2256 (1999)
Hershberger, J., Suri, S., Yıldız, H.: A near-optimal algorithm for shortest paths among curved obstacles in the plane. In: Proceedings of the Twenty-Ninth Annual Symposium on Computational Geometry, pp. 359–368 (2013)
Kapoor, S., Maheshwari, S.N.: Efficient algorithms for Euclidean shortest path and visibility problems with polygonal obstacles. In: Proceedings of the Fourth Annual Symposium on Computational Geometry, pp. 172–182 (1988)
Kirkpatrick, D.: Optimal search in planar subdivisions. SIAM J. Comput. 12(1), 28–35 (1983)
Lee, D.T., Preparata, F.P.: Euclidean shortest paths in the presence of rectilinear barriers. Networks 14(3), 393–410 (1984)
Maheshwari, A., Nandy, S.C., Pattanayak, D., Roy, S., Smid, M.: Geometric path problems with violations. Algorithmica 80, 1–24 (2016)
Matoušek, J.: On geometric optimization with few violated constraints. Discret. Comput. Geom. 14(4), 365–384 (1995)
Mitchell, J.S.B.: A new algorithm for shortest paths among obstacles in the plane. Ann. Math. Artif. Intell. 3(1), 83–105 (1991)
Mitchell, J.S.B.: Shortest paths among obstacles in the plane. Int. J. Comput. Geom. Appl. 6(3), 309–332 (1996)
Mitchell, J.S.B., Papadimitriou, C.H.: The weighted region problem: finding shortest paths through a weighted planar subdivision. J. ACM (JACM) 38(1), 18–73 (1991)
Overmars, M.H., Welzl, E.: New methods for computing visibility graphs. In: Proceedings of the Fourth Annual Symposium on Computational Geometry, pp. 164–171 (1988)
Rohnert, H.: Shortest paths in the plane with convex polygonal obstacles. Inf. Process. Lett. 23(2), 71–76 (1986)
Roos, T., Widmayer, P.: \(k\)-violation linear programming. Inf. Process. Lett. 52(2), 109–114 (1994)
Storer, J.A., Reif, J.H.: Shortest paths in the plane with polygonal obstacles. J. ACM (JACM) 41(5), 982–1012 (1994)
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Funding was provided by National Science Foundation (Grant No. CCF-1525817).
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A preliminary version of this paper [17] appeared in the Proceedings of the 25th European Symposium of Algorithms (ESA), 2017.
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Hershberger, J., Kumar, N. & Suri, S. Shortest Paths in the Plane with Obstacle Violations. Algorithmica 82, 1813–1832 (2020). https://doi.org/10.1007/s00453-020-00673-y
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DOI: https://doi.org/10.1007/s00453-020-00673-y