A linear approximate-size random sampler for labelled planar graphs

Eric Fusy (1)

1 ALGORITHMS - Algorithms

This article introduces a new algorithm for the random generation of labelled planar graphs. Its principles rely on Boltzmann samplers, as recently developed by Duchon, Flajolet, Louchard, and Schaeffer. It combines the Boltzmann framework, a suitable use of rejection, a new combinatorial bijection found by Fusy, Poulalhon and Schaeffer, as well as a precise analytic description of the generating functions counting planar graphs, which was recently obtained by Giménez and Noy. This gives rise to an extremely efficient algorithm for the random generation of planar graphs. There is a preprocessing step of some fixed small cost. Then, the expected time complexity of generation is quadratic for exact-size uniform sampling and linear for approximate-size sampling. This greatly improves on the best previously known time complexity for exact-size uniform sampling of planar graphs with $n$ vertices, which was a little over $\mathcal{O}(n^7)$.

Mots clés: Random generation; Boltzmann sampling; Planar graphs

Domaines: Combinatoire [math.CO]

Eric Fusy. A linear approximate-size random sampler for labelled planar graphs. 2007. ⟨hal-00145255v1⟩