METATWW solver for pace-2023

The topic of the PACE (Parameterized Algorithms and Computational Experiments) 2023 challenge (https://pacechallenge.org/2023/) is twinwidth (https://en.wikipedia.org/wiki/Twin-width). In the heuristic track of PACE 2023 the aim is to find contraction sequences of small width. Our solver, METATWW, uses a two-phase approach. In phase one it finds an initial contraction sequence by contracting pairs of vertices where the size of the symmetric difference between their neighbourhoods is small. In phase two we iteratively move contractions around within specific intervals of the contraction sequence in order to reduce the width of the sequence.

Contact: williambillemeyling@gmail.com (William Bille Meyling)