Recognizing Weakly Simple Polygons
Hugo A. Akitaya, Greg Aloupis, Jeff Erickson, Csaba D. Tóth · arXiv (Cornell University) · 2016
We present an $O(n\log n)$-time algorithm that determines whether a given planar $n$-gon is weakly simple. This improves upon an $O(n^2\log n)$-time algorithm by Chang, Erickson, and Xu (2015). Weakly simple polygons are required as input for several geometric algorithms. As such, how to recognize simple or weakly simple polygons is a fundamental question.