🤖 AI Summary
This study addresses the existence and construction of compatible triangulations between two simple polygons with the same number of vertices and a given vertex correspondence. The work proposes efficient algorithms for two scenarios: when a triangulation of one polygon is provided, it determines in $O(n \log n + nr)$ time whether a compatible triangulation exists for the other polygon; when only the vertex correspondence is given, it constructs a compatible triangulation—if one exists—in $O(M(n))$ time, where $M(n)$ denotes the complexity of matrix multiplication. By integrating techniques from computational geometry, including triangulation methods, reflex vertex analysis, and fast matrix multiplication, the approach achieves near-optimal theoretical complexity, substantially improving the efficiency of both decision and construction procedures for compatible triangulations.
📝 Abstract
Let $P$ and $Q$ be simple polygons with $n$ vertices each. We wish to compute triangulations of $P$ and $Q$ that are combinatorially equivalent, if they exist. We consider two versions of the problem: if a triangulation of $P$ is given, we can decide in $O(n\log n + nr)$ time if $Q$ has a compatible triangulation, where $r$ is the number of reflex vertices of $Q$. If we are already given the correspondence between vertices of $P$ and $Q$ (but no triangulation), we can find compatible triangulations of $P$ and $Q$ in time $O(M(n))$, where $M(n)$ is the running time for multiplying two $n\times n$ matrices.