Trajectory Minimum Touching Ball

Published: 2025, Last Modified: 25 Jan 2026CoRR 2025EveryoneRevisionsBibTeXCC BY-SA 4.0
Abstract: We present algorithms to find the minimum radius sphere that intersects every trajectory in a set of $n$ trajectories composed of at most $k$ line segments each. When $k=1$, we can reduce the problem to the LP-type framework to achieve a linear time complexity. For $k \geq 4$ we provide a trajectory configuration with unbounded LP-type complexity, but also present an almost $O\left((nk)^2\log n\right)$ algorithm through the farthest line segment Voronoi diagrams. If we tolerate a relative approximation, we can reduce to time near-linear in $n$.
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