A bijection for triangulations of a polygon with interior points and multiple edges

  • Authors:
  • Dominique Poulalhon;Gilles Schaeffer

  • Affiliations:
  • LIX, École polytechnique, 91128 Palaiseau, Cedex, France;CNRS-LORIA, Campus Science, B.P. 239, 54506 Vandoeuvre, France

  • Venue:
  • Theoretical Computer Science - Random generation of combinatorial objects and bijective combinatorics
  • Year:
  • 2003

Quantified Score

Hi-index 0.00

Visualization

Abstract

Loopless triangulations of a polygon with k vertices in k + 2n triangles (with interior points and possibly multiple edges) were enumerated by Mullin in 1965, using generating functions and calculations with the quadratic method.In this article we propose a simple bijective interpretation of Mullin's formula. The argument rests on the method of conjugacy classes of trees, a variation of the cycle lemma designed for planar maps. In the much easier case of loopless triangulations of the sphere (k = 3), we recover and prove correct an unpublished construction of the second author.