Heyawake is a type of shading logic puzzle, in which solvers must shade squares. Shaded cells may not touch each other and unshaded cells must form a contiguous region. There are additionally marked regions in the grid, some with numbers. Regions with numbers must have that exact number of shaded cells. Additionally, a horizontal or vertical run of unshaded cells cannot cross over two region borders.

Background[edit | edit source]

Hitori was first introduced in Puzzle Communication Nikoli #39 in 1992, invented by Hiroyuki Fukushima. The name means "dividing rooms".[1] Traditionally, the rooms (marked regions) are rectangular in shape. When this constraint isn't followed, this is sometimes known as Heyawacky, a term first coined by Thomas Snyder in 2009. Such puzzles can also include internal borders as well.

Other Variants[edit | edit source]

Ayeheya / Ekawayeh - Additionally, shaded cells in all rooms must be rotationally symmetric across the center of the room.

Akichiwake - First created by Prasanna Seshadri in 2014. Numbers instead denote the maximum size of contiguous unshaded cells in a given region.

Heyasleep - first coined by Prasanna Seshadri in 2012[2], although the variant is essentially equivalent to Heyawake. Later on, a variant with the same name by David Millar was created in 2018, with marked squares that signify being connected to only a single unshaded square.[3]. (Note that the pun only works orthographically, as heyawake is not pronounced like "awake".)

Heyacrazy - The heyawake "an orthogonal unshaded line cannot cross two borders" is generalized to include lines of any direction. First invented by Deusovi in 2019.[4]

Puzzle Application[edit | edit source]

An example Heyawake puzzle
The solution to the above puzzle

To do TO DO

Strategy[edit | edit source]

To do TO DO

Examples[edit | edit source]

To do TO DO

See Also[edit | edit source]

References[edit | edit source]