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Strategies for Popular Number Puzzles
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Stripy numbers Referred to in strategy results are:

1 2 3 4 5 6 7 8 9
9 1 2 3 4 5 6 7 8
8 9 1 2 3 4 5 6 7
7 8 9 1 2 3 4 5 6
6 7 8 9 1 2 3 4 5
5 6 7 8 9 1 2 3 4
4 5 6 7 8 9 1 2 3
3 4 5 6 7 8 9 1 2
2 3 4 5 6 7 8 9 1
Free Sudoku and Str8ts for Print
Stripy Sudoku Solver
Solve Path now excludes unchecked strategies
Candidates can be Edited or Highlighted Chained Coloured,  Shown
Enter clues or solutions
1 2 3 4 5 6 7 8 9
Auto Tab Auto Clear
Clues+Solved: 0/81
Pick an example here

Puzzle Rules
Enter the numbers 1 to 9 uniquely in every row, column, box and each 'stripe'. Note that the stipes wrap around and all but one are in two parts.

Pick an example from the list and use [Take Step] to click through the steps of the solver so see how each puzzle solves.
Show bi-values cells
Show Strong (bi-location) links in
Boxes Rows Columns
1 2 3 4 5 6 7 8 9
Version 2.24
See Strategy Overview documentation

Coordinate system: Letter/Number rYcX

Check for Solved Cells   
Show Possibles  
 1: Singles  
 2: Pairs  
 3: Triples 
 4: Quads 
 5: Pointing Pairs  
 6: Box/Line Reduction  
Tough Strategies
 7: X-Wing  
 8: Simple Colouring  
 9: Y-Wing  
10: Rectangle Elimination  
11: Swordfish  
12: XYZ Wing  
Diabolical Strategies
13: X-Cycles  
14: XY-Chain  
15: 3D Medusa  
16: Jellyfish  
17: WXYZ Wing  
Extreme Strategies
19: Grouped X-Cycles  
20: Finned X-Wing  
21: Finned Swordfish  
22: Altern. Inference Chains 
23: Sue-de-Coq  
24: Digit Forcing Chains  
25: Nishio Forcing Chains 
26: Cell Forcing Chains  
27: Unit Forcing Chains  
28: Almost Locked Sets  
29: Death Blossom  
30: Pattern Overlay Method  
31: Quad Forcing Chains  
"Trial and Error"
32: Bowman's Bingo 

Note: All Chaining strategies now permit cycling alternatives, where found read more

Errors? [CRTL]+[F5] to clear and download the latest script files

The Stripy Sudoku Solver

This solver is tentative while I figure out how to make this variant. For some reason I can't fathom yet the usual code to fill a board prior to making a puzzle simple won't fill. I'm hoping it's a simple code issue but will be interesting if it is a special property of the puzzle. So only one example I can give. But you can try subtracting clues to make a harder puzzle. Take the grade with a pinch of salt.

Stripy is the same puzzle as normal Sudoku but with an extra constraint. In a similar way to the rows, columns an boxes, the stripes must also be uniquely 1 to 9. All Sudoku strategies continue to apply - except the ones that rely on the deadly pattern used by Uniqueness strategies.

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.

Version 2.19 (June 12th 2024)
Added Stripy Sudoku

Full version history here

Solver help

Use the "Import a Sudoku" button or type in a Sudoku puzzle in the small board.
You can also pick examples from the list above. Click on Take Step to step through the solution. Unknown squares are filled with 'candidates' - possible solutions.
Any cells that are reduced to one possible candidate are solved.

You can use the [<<] button to step back one go. Toggling between Take Step and [<<] helps you see the changes.

Pressing "Enter" on the keyboard after clicking on Take Step is a quick way to activate "Take Step". Details of any solutions will be written out in the text box below the big board. Strategies are ordered by complexity. Any strategy that is successful returns the step-through to the start.

Click on the board to highlight sets of numbers. You can edit the Sudoku at any time - entering solutions in the small board or editing candidates. (Toggle between highlighting and editing using the radio buttons at the top.)

All Solutions to a Stripy Sudoku
By Andrew Stuart and Rui Gonçalves, Syndicated Puzzles
Email your puzzle to a friend
Copy and paste the contents of the green box into your email program and send it off.
The links contain the puzzle which will load when your friend visits the Sudoku Solver.
Solver created on 11-Nov-2015.
This page was last modified on 1-Ju1-2024.
All code and design is copyright and for personal use only and may not be reproduced elsewhere.
Copyright Andrew Stuart @ Syndicated Puzzles, 2005-2023, Privacy