Corpus ID: 236425582

Filling Crosswords is Very Hard

@article{Gourvs2021FillingCI,
  title={Filling Crosswords is Very Hard},
  author={Laurent Gourv{\`e}s and Ararat Harutyunyan and Michael Lampis and Nikolaos Melissinos},
  journal={ArXiv},
  year={2021},
  volume={abs/2109.11203}
}
We revisit a classical crossword filling puzzle which already appeared in Garey&Jonhson’s book. We are given a grid with n vertical and horizontal slots and a dictionary with m words and are asked to place words from the dictionary in the slots so that shared cells are consistent. We attempt to pinpoint the source of intractability of this problem by carefully taking into account the structure of the grid graph, which contains a vertex for each slot and an edge if two slots intersect. Our main… 

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