Grid Coloring Problem solver

GCP solver written in rust using varisat.

Grid Coloring Problem GCP:

The n×n grid is 4-colorable if there is a way to 4-color the vertices of the n×n grid so that there is no rectangle with all four corners the same color.

See also:

Extremely Complex 4-Colored Rectangle-Free Grids Solution of Open Multiple-Valued Problems. doi:10.1109/ISMVL.2012.12