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Jigsaw Sudoku Solver Please report any bugs. Tested in IE, Firefox, Safari and Chrome
 Feedback: Form and User Comments/Questions Here
 
Candidates can be Edited or Highlighted
Enter numbers here: (tabbing works well)
1 2 3 4 5 6 7 8 9
Step 1: Choose the 'shape'
Step 2: Pick an example here

Quick help: The differences

Jigsaw Sudokus are the same as normal sudoku except for the shapes of the boxes. Some strategies cannot be used (see below) but there is one important addition: The Law of Leftovers.

In order to use this solver you need to pick the correct grid shape from the list above. Only then type the numbers into the small grid, use the Import button or pick an example from the example list.

There are 20 Jigsaw shapes as used on www.sudoku.org.uk and four interesting examples for each shape, 80 examples in total.

For all other help guides for the solver, see the Sudoku Solver.

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Version 1.66
See the Strategy Home Page for strategy guides.
Coordinate system: Letter/Number rYcX


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9
Show Candidates
Check for Solved Squares   
Show Possibles  
1: Singles in Row/Col   
2: Singles in Box  
3: Naked Pairs/Triples  
4: Hidden Pairs/Triples 
5: Naked Quads 
6: Pointing Pairs  
7: Box/Line Reduction  
Tough Strategies
8: Law of Leftovers  
9: X-Wing  
10: Simple Colouring  
11: Y-Wing  
12: Sword-Fish  
Diabolical Strategies
13: X-Cycles  
14: XY-Chain  
15: 3D Medusa  
16: Jelly-Fish  
17: XYZ Wing / WXYZ Wing  
18: Aligned Pair Exclusion  
Extreme Strategies
19: Grouped X-Cycles  
20: Altern. Inference Chains 
21: Digit Forcing Chains  
22: Cell Forcing Chains  
23: Unit Forcing Chains  
24: Almost Locked Sets  
25: Death Blossom  
26: Pattern Overlay Method  
27: Quad Forcing Chains  
"Trial and Error"
28: Nishio 
29: Bowman Bingo 


Please report any bugs - Thanks.


Welcome to my Jigsaw Sudoku page

I am pleased to reveal this latest Sudoku Solver - one for Jigsaw sudokus. In many ways Jigsaw's are even more interesting than normal sudokus, although they have not been studied as much.

All bar a few of the strategies pertain to Jigsaws, but in the current version I have removed Uniqueness tests until I can check the algorithms more properly. However, you will rarely need an extreme strategy since they are often defeated using no more than Pointing Pairs and Box/Line Removal - simple because the shapes of the boxes lead to more opportunities for these strategies. Also, the Law of Leftovers is an excellent candidate eliminator. Documentation on this to follow.



All feedback, comments, arguments, bug reports and strategy ideas are welcome. There is a new FEEDBACK form with a column displaying comments and questions. Many thanks to all the people who have done so and helped improve this solver.

New in version 1.64 (March 10th 2010)
Fixed a series of bugs with editing candidates in the large board.

New in version 1.63 (March 3rd 2010)
3D Medusa and much improved forcing chains. A new system of symbolising chains.

Version history here

New in version 1.38 (November 21st 2006)
Release of the Jigsaw Solver




Solver created on 31-Mar-2007.

This page was last modified on 05-March-2010.
All code and design is copyright and for personal use only and may not be reproduced elsewhere.
Copyright Andrew Stuart @ Scanraid Ltd, 2005-2009