Rooted: Created page with "'''Windoku''', '''NRC-Sudoku''', '''Hypersudoku''', '''Sudoku Hyper''', or '''Four-square Sudoku''' is a Sudoku Variant with additional constraints. This format was fi..."

2022-01-20T03:39:22Z

Created page with "'''Windoku''', '''NRC-Sudoku''', '''Hypersudoku''', '''Sudoku Hyper''', or '''Four-square Sudoku''' is a Sudoku Variant with additional constraints. This format was fi..."

New page

'''Windoku''', '''NRC-Sudoku''', '''Hypersudoku''', '''Sudoku Hyper''', or '''Four-square Sudoku''' is a [[Sudoku Variant]] with additional [[constraint]]s. This format was first introduced in the Dutch newspaper ''NRC Handelsblad'' by Peter Ritmeester and the first playable online version by Chris McCusker.

== Hidden Constraints ==
Although there are only 4 additional constraints (the 4 window panes) highlighted by the puzzle maker, the position of these 4 window panes indirectly creates 5 additional constraints. These are shown in the following picture.

[[Image:Windoku regions.png]]
; 1. Top-Left window pane
: the cyan 9 cells in rows 2, 3, 4 and columns 2, 3, 4
; 2. Top-Right window pane
: the yellow 9 cells in rows 2, 3, 4 and columns 6, 7, 8
; 3. Bottom-Left window pane
: the red 9 cells in rows 6, 7, 8 and columns 2, 3, 4
; 4. Bottom-Right window pane
: the green 9 cells in rows 6, 7, 8 and columns 6, 7, 8
; 5. Top Stiles
: The top-left window pane and the top-right window pane each require digits 1-9. This leaves the magenta cells for rows 2, 3 and 4 with the remaining set of 1-9.
; 6. Bottom Stiles
: The bottom-left window pane and the bottom-right window pane each require digits 1-9. This leaves the grey cells for rows 6, 7 and 8 with the remaining set of 1-9.
; 7. Left Rails
: The Top-left window pane and the bottom-left window pane each require digits 1-9. This leaves the light brown cells for columns 2, 3 and 4 with the remaining set of 1-9.
; 8. Right Rails
: The Top-right window pane and the bottom-right window pane each require digits 1-9. This leaves the dark cyan cells for columns 6, 7 and 8 with the remaining set of 1-9.
; 9. Corners
: All the cells in the grid belong to non-overlapping groups, except the white cells. This is the last group which requires digits 1-9.

== Solving Techniques ==
The [[solving technique]]s for a Windoku are similar to those of regular Sudoku. The extra constraints are placed in such a way that there are many more [[intersection]]s to deal with. Each additional constraint can contain [[subset]]s and [[strong link]]s which could be used in [[coloring]] techniques.

There are fewer [[Unique Rectangle]]s in the grid, because not all 468 possible unique rectangles for a standard Sudoku are located in exactly 2 additional houses.

== Minimum Number of Givens ==
[[Valid]] Windokus with 11 [[given]]s exist. However, it is not known whether this is the minimum number of givens. See [http://homepages.cwi.nl/~aeb/games/sudoku/nrc11.html this page] for examples for such Windokus.

== External Link ==

== See Also ==
* [[Sudoku-X]]
* [[Center Dot]]
* [[Asterisk]]

[[Category: Sudoku Variants]]

Windoku - Revision history

Rooted: Created page with "'''Windoku''', '''NRC-Sudoku''', '''Hypersudoku''', '''Sudoku Hyper''', or '''Four-square Sudoku''' is a Sudoku Variant with additional constraints. This format was fi..."