Flip Distance Between Triangulations of a Simple Polygon is NP-Complete

@article{Aichholzer2015FlipDB,
  title={Flip Distance Between Triangulations of a Simple Polygon is NP-Complete},
  author={Oswin Aichholzer and Wolfgang Mulzer and Alexander Pilz},
  journal={Discrete \& Computational Geometry},
  year={2015},
  volume={54},
  pages={368-389}
}
Let T be a triangulation of a simple polygon. A flip in T is the operation of replacing one diagonal of T by a different one such that the resulting graph is again a triangulation. The flip distance between two triangulations is the smallest number of flips required to transform one triangulation into the other. For the special case of convex polygons, the problem of determining the shortest flip distance between two triangulations is equivalent to determining the rotation distance between two… 
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