Untangling a Polygon

Pach, János and Tardos, Gábor (2002) Untangling a Polygon. In: Graph Drawing 9th International Symposium, GD 2001, September 23-26, 2001, Vienna, Austria , pp. 154-161 (Official URL: http://dx.doi.org/10.1007/3-540-45848-4_13).

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The following problem was raised by M. Watanabe. Let P be a self-intersecting closed polygon with n vertices in general position. How manys steps does it take to untangle P, i.e., to turn it into a simple polygon, if in each step we can arbitrarily relocate one of its vertices. It is shown that in some cases one has to move all but at most O((n log n)2/3) vertices. On the other hand, every polygon $P$ can be untangled in at most n − Ω(√n) steps. Some related questions are also considered.

Item Type:Conference Paper
Additional Information:10.1007/3-540-45848-4_13
Classifications:Z Theory > Z.250 Geometry
G Algorithms and Complexity > G.560 Geometry
ID Code:508

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