A grid-based logic puzzle
Color each cell black or white… and give your brain a workout.
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Parity
If you see an arrow in a cell, there must be the same number of black and white cells in the direction face by the arrow. A cell can contain a double-headed arrow, this means that both sides of the cell must respect the parity rule.
For example, here we know that this cell must be white because the arrow is pointing at 2 cells and one of them is already black.
When the arrow is double, it applies to both sides.
This one already has one black and one white cells above it but only has one black cell bellow it, the other one must be white.
