## Irregular X-sudoku

For fans of Killer Sudoku, Samurai Sudoku and other variants

### Irregular X-sudoku

125439002_2278010265678784_3475768094186885609_o.jpg (7.53 KiB) Viewed 179 times
urhegyi

Posts: 107
Joined: 13 April 2020

### Re: Irregular X-sudoku

2020-11-19 (4).png (82.65 KiB) Viewed 83 times
Last edited by urhegyi on Thu Nov 19, 2020 10:12 pm, edited 1 time in total.
urhegyi

Posts: 107
Joined: 13 April 2020

### Re: Irregular X-sudoku

You solved your own puzzle... How?

Hajime

Posts: 231
Joined: 20 April 2018
Location: Netherlands

### Re: Irregular X-sudoku

SudokuSolver - u have to define jigsaw regions, and select X - this JigsawX is solved, singles only.
JSudoku - u have to define jigsaw regions, and select X - this JigsawX is solved, singles only.
SudokuJigsawExplainer will also can be used to solve this, but u have to do the X candidate eliminations!
Code: Select all
`........................6.....8..2..1.5....748....2........3..9.4.....1....2.6... 111122222111112222333345555366445555366445777368447777368447799368889999668888999 JSXSumoCueV1D=0J0=0J0=0J0=0J0=0J1=0J1=0J1=0J1=0J1=0J0=0J0=0J0=0J0=0J0=0J1=0J1=0J1=0J1=0J2=0J2=0J2=0J2=0J3=0J4=6J4=0J4=0J4=0J2=0J5=0J5=8J3=0J3=0J4=2J4=0J4=0J4=1J2=0J5=5J5=0J3=0J3=0J4=0J6=7J6=4J6=8J2=0J5=0J7=0J3=0J3=2J6=0J6=0J6=0J6=0J2=0J5=0J7=0J3=0J3=3J6=0J6=0J8=9J8=0J2=4J5=0J7=0J7=0J7=0J8=0J8=1J8=0J8=0J5=0J5=0J7=2J7=0J7=6J7=0J8=0J8=0J8+---------------+-------------------+| .   .   .   . | .   .   .   .   . ||               +---+               || .   .   .   .   . | .   .   .   . |+---------------+---+---------------+| .   .   .   . | . | .   6   .   . ||   +-------+---+   |               || . | .   . | 8   . | .   2   .   . ||   |       |       |   +-----------+| 1 | .   5 | .   . | . | .   7   4 ||   |   +---+       +---+           || 8 | . | . | .   . | 2   .   .   . ||   |   |   |       |       +-------+| . | . | . | .   . | 3   . | .   9 ||   |   |   +-------+-------+       || . | 4 | .   .   . | .   .   1   . |+---+   |           +---+           || .   . | .   2   .   6 | .   .   . |+-------+---------------+-----------+`

Edit: fixed SumoCue definition.
Last edited by 1to9only on Thu Nov 19, 2020 5:27 pm, edited 2 times in total.
1to9only

Posts: 2127
Joined: 04 April 2018

### Re: Irregular X-sudoku

Hajime wrote:You solved your own puzzle... How?

It was posted with 5 stars (the maximum) and very challenging. But I tried myself and like in most newspapers or apps this does not mean they are very hard.
I solved with pencil on paper and found only singles, but it was a good start to discover more.
1to9only wrote:You have to do the X candidate eliminations yourself

I didn't know you can use jigsawexplainer when the solution is not unique because of the diagonal blocks are not(yet) implemented.
urhegyi

Posts: 107
Joined: 13 April 2020

### Re: Irregular X-sudoku

urhegyi wrote:I didn't know you can use jigsawexplainer when the solution is not unique because of the diagonal blocks are not(yet) implemented.

I've corrected my previous post - when I get the multiple solutions message, i scan the diagonals and manually eliminate candidates - had to do this a few times!
Implementing X in the JigsawExplainer would be nice, but this is low priority on my list of things to do...
1to9only

Posts: 2127
Joined: 04 April 2018

### Re: Irregular X-sudoku

2020-11-19 (1).png (24.59 KiB) Viewed 122 times
urhegyi

Posts: 107
Joined: 13 April 2020

### Re: Irregular X-sudoku

And here is a puzzle with the same layout that also needs some generalized intersections
XJS.PNG (4.08 KiB) Viewed 108 times

The puzzle is also with diagonals (XSudoku), not shown in above image.
Code: Select all
`#1//B4,XJS2..19.............................2.45....3.2....6...........9...6......73.5..2..111122222111112222333345555366445555366445777368447777368447799368889999668888999`

Hajime

Posts: 231
Joined: 20 April 2018
Location: Netherlands

### Re: Irregular X-sudoku

2020-11-19 (2).png (24.54 KiB) Viewed 101 times
I will give it a try, Thanks
urhegyi

Posts: 107
Joined: 13 April 2020

### Re: Irregular X-sudoku

There is a certain logic in both puzzles. They share the same pattern: the first four digits in row 1 are the last 4 digits of row 2 and the last five digits of row 1 are the same as the first five digits of row 2. And there are more similarities comparing the two puzzles. Can you explain how you created the second from the first? One thing I can say: when I not discovered the way of shuffling solving would be a lot more difficult because of the many locked candidates(pointing and claiming). I also have to find out how the generalized intersections actually work. I'm used to work with the classical intersections.
urhegyi

Posts: 107
Joined: 13 April 2020

### Re: Irregular X-sudoku

SudokuJigsawExplainer finds far too many generalized intersections. It's a BUG! I'll fix this next week.
1to9only

Posts: 2127
Joined: 04 April 2018

### Re: Irregular X-sudoku

2020-11-19 (3).png (81.19 KiB) Viewed 83 times
urhegyi

Posts: 107
Joined: 13 April 2020

### Re: Irregular X-sudoku

urhegyi wrote:There is a certain logic in both puzzles. ... Can you explain how you created the second from the first?

It is exactly the same puzzle, but only the digits have been swapped. there are 9! possibilities for this puzzle
Eg. all 4's became 2's.

urhegyi wrote:I also have to find out how the generalized intersections actually work. I'm used to work with the classical intersections.

in http://forum.enjoysudoku.com/generalized-methods-t38209.html I try to explain generalized intersections (and generalized kites).
You always need some extra constraints, like the diagonals, to lock a single digit into 3 or more houses.

Here is a new one XJS with the same layout, so also with diagonals. You need some chains...
And the puzzle is a different one than the above.
XJS_hard.PNG (14.12 KiB) Viewed 69 times

Code: Select all
`#1//B4,XJS...4.2....2.....7.91..8..45...........................29..4..61.4.....9....6.9...111122222111112222333345555366445555366445777368447777368447799368889999668888999`

Hajime

Posts: 231
Joined: 20 April 2018
Location: Netherlands

### Re: Irregular X-sudoku

2020-11-20.png (23.85 KiB) Viewed 59 times
urhegyi

Posts: 107
Joined: 13 April 2020

### Re: Irregular X-sudoku

2020-11-20 (7).png (83.07 KiB) Viewed 57 times
urhegyi

Posts: 107
Joined: 13 April 2020

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