,
Daniel Lokshtanov
Creative Commons Attribution 3.0 Unported license
Given two points in the plane, a set of obstacles defined by closed curves, and an integer k, does there exist a path between the two designated points intersecting at most k of the obstacles? This is a fundamental and well-studied problem arising naturally in computational geometry, graph theory, wireless computing, and motion planning. It remains NP-hard even when the obstacles are very simple geometric shapes (e.g., unit-length line segments). In this paper, we show that the problem is fixed-parameter tractable (FPT) parameterized by k, by giving an algorithm with running time k^O(k³) n^O(1). Here n is the number connected areas in the plane drawing of all the obstacles.
@InProceedings{eiben_et_al:LIPIcs.SoCG.2020.39,
author = {Eiben, Eduard and Lokshtanov, Daniel},
title = {{Removing Connected Obstacles in the Plane Is FPT}},
booktitle = {36th International Symposium on Computational Geometry (SoCG 2020)},
pages = {39:1--39:14},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-143-6},
ISSN = {1868-8969},
year = {2020},
volume = {164},
editor = {Cabello, Sergio and Chen, Danny Z.},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.SoCG.2020.39},
URN = {urn:nbn:de:0030-drops-121972},
doi = {10.4230/LIPIcs.SoCG.2020.39},
annote = {Keywords: parameterized complexity and algorithms, planar graphs, motion planning, barrier coverage, barrier resilience, colored path, minimum constraint removal}
}