The New Sudoku Players' Forum

[m_b_metcalf]

I am like you on that one Mike. I try for symmetrically minimal if I can't do Symmetrical & minimal

I have a new algorithm functioning, but it needs more work and I'm away now for a week. Watch this space.

Mike

[m_b_metcalf]

Upthread I posted my first attempt at a windmill-x:

Code: Select all

......................4....................18.............................6......  TL
..5........8.....................8.......2.................................1..9..  TR
.................................................................................   M
...1..........5......8..............................................4..........5.  BL
.................7..........1.............8......4.23........4...2.........81....  BR
25 clues, minimal(?), all diagonals empty, central puzzle empty.


However, crient correctly pointed out that it wasn't, in fact minimal, and found 10 clues (listed oddly by column/row) that are, individually,
redundant. I have now implemented some new code, and agree with his list.

[rubbish deleted]

Mike Metcalf

[blue]

Upthread I posted my first attempt at a windmill-x:

Code: Select all

......................4....................18.............................6......  TL
..5........8.....................8.......2.................................1..9..  TR
.................................................................................   M
...1..........5......8..............................................4..........5.  BL
.................7..........1.............8......4.23........4...2.........81....  BR
25 clues, minimal(?), all diagonals empty, central puzzle empty.


However, crient correctly pointed out that it wasn't, in fact minimal, and found 10 clues (listed oddly by column/row) that are, individually,
redundant. I have now implemented some new code, and agree with his list. Moreover, I find that an additional clue
is also redundant, namely r18c17:3.

Hi Mike,

Sorry, but 3r18c17 wasn't redundant in the original puzzle ( and your new puzzle has several solutions ).
The original puzzle with 3r18c17 removed, has 3 solutions.

Hidden Text: Show

Code: Select all

458719263392586471761342589647821935529463718813975642174258396985637124236194857  TL
265371489438295716791684235174536892589742361623819547917458623856923174342167958  TR
258396174637124589194857623825643917349712856761985342982431765473568291516279438   M
637149825812765349495832761763451982158296473924387516376518294581924637249673158  BL
431765928568291437279438651615382794724956813893147265387529146142673589956814372  TR

438712965592386471761549283647821539259463718813975642174258396985637124326194857  TL
265371489438295716791684235174536892589742361623819547917458623856923174342167958  TR
258396174637124589194857623825643917349712856761985342982431765473568291516279438   M
637149825812765349495832761763451982158296473924387516376518294581924637249673158  BL
431765928568291437279438651615382794724956813893147265387529146142673589956814372  TR

-- original solution
458719236613582479729643581347821965592436718861975342174258693985367124236194857  TL
235671489468295713791384265174563892589742631326819547917458326853926174642137958  TR
258693174367124589194857326825346917649712853731985642982461735476538291513279468   M
367149825812735649495862731736451982158293476924687513673518294581924367249376158  BL
461735928538291467279468351315682794724953816896147235687529143142376589953814672  TR


[m_b_metcalf]

Sorry, but 3r18c17 wasn't redundant in the original puzzle ( and your new puzzle has several solutions ).
The original puzzle with 3r18c17 removed, has 3 solutions.

blue, thanks. I'll investigate.

Regards,

Mike

[creint]

Here my first try Windoku Kazaguruma / Windmill X with 19 clues and minimal:

Code: Select all

................7.............8...............6......2...........................
............2.........8............................5.7.....8.....................
..............................................3........................1.........
..................4......3...6.........................................7.........
..............1..................7...............4....6..5................3......

Really easy to generate, every design now possible.

Here two 8x8 with rows/columns and only center 4 normal boxes, compressed windoku latin square sudoku

Hidden Text: Show

Code: Select all

.7.8..1...6
8....4..6.
9..6.....4
.....7..
5.9...7...2
3.....9..
..4....8.7
1..3.4.5...8

Code: Select all

9..1...4.7.5
...5.2...4
..9...8..
..7..9.3..
2..4.9..6..
3.....9..
.5......7
7.6.....1.8

[m_b_metcalf]

[More rubbish deleted]

[blue]

Hi Mike,

Multiple solutions again

[m_b_metcalf]

Multiple solutions again

One last shot at getting my stack of if-statements right:

Code: Select all

......................4....................18.............................6......  TL
..5........8.....................8.......2.................................1..9..  TR
.................................................................................   M
...1.................8..............................................4............  BL
.................7..........1.............8.........3........4...2.........81....  BR

21 clues, minimal + 1, all diagonals empty, central puzzle empty.

Thanks,

Mike

[blue]

Hi Mike,

It has a single solution, but it isn't quite minimal.
There are two individually redundant clues.
Removing either one, leaves a minimal puzzle.

Redundant clues: don't look, except as last resort

Hidden Text: Show

8r17c16 (8r5c7 in BR)
1r21c14 (1r9c5 in BR)

Best Regards,
Blue.

[m_b_metcalf]

It has a single solution, but it isn't quite minimal.

blue, Many thanks. I see the problem but will leave its solution to another time. At least it's now a valid puzzle that enxio27 can tackle. I was very surprised that a non-central sub-puzzle can have so few as only three clues.

Regards,

Mike

[tarek]

I’m aiming to look at puzzles posted to confirm validity and solution which also serves to test the integrity of my solver/generator as well. Thanks to all for their contributions!

Tarek

[enxio27]

blue, Many thanks. I see the problem but will leave its solution to another time. At least it's now a valid puzzle that enxio27 can tackle.

Yay!! Thank you!!

[m_b_metcalf]

Before putting my Windmill X code into mothballs, I thought I'd generate a couple of puzzles that can be solved by humans using basic techniques. Two are below. Each has an empty central puzzle and has rotational symmetry.

Regards,

Mike

Code: Select all

 . . . . . . 4 1 . 3 . . . . . . . . . . .
 . . . . . . . . 3 . . . . . . . . . . . .
 . . . . . . 9 . . 7 8 . . . . . . . . . .
 . . . . 3 . . . . . . 8 . . . . 7 . . . .
 . . . . . . . 5 . . . 7 . 6 . . . 9 1 . .
 . . . . . . . . 6 . . . . 9 2 . . 5 . . .
 . . . . . . . . . . . . . . . 7 . . . . .
 . . . . . 4 . . . . . . . . . . . . 8 5 .
 . . . . . . . . . . . . . . . . . . 6 3 .
 . . . . . . . . . . . . . . . . . . . . .
 . . . . . 9 . . . . . . . . . 5 . . . . .
 . . . . . . . . . . . . . . . . . . . . .
 . 4 5 . . . . . . . . . . . . . . . . . .
 . 3 6 . . . . . . . . . . . . 5 . . . . .
 . . . . . 5 . . . . . . . . . . . . . . .
 . . . 4 . . 1 9 . . . . 5 . . . . . . . .
 . . 7 5 . . . 6 . 8 . . . 3 . . . . . . .
 . . . . 7 . . . . 5 . . . . . . 4 . . . .
 . . . . . . . . . . 8 5 . . 6 . . . . . .
 . . . . . . . . . . . . 2 . . . . . . . .
 . . . . . . . . . . . 2 . 1 7 . . . . . .

 Number of clues  52 

...41.3.......3......9..78..3......8....5...7.....6..............4............... TL
....7.....6...91...92..5......7...........85.......63.............5.............. TR
................................................................................. M
..............9.............45.......36...........5......4..19...75...6.....7.... BL
...............5..............5.....8...3....5......4..85..6......2.......2.17... BR


Code: Select all

 . . . . . . . . . . . . . . . . . . . . .
 . . . 9 . . . . 3 . 4 . . . . . . . . . .
 . . . . . . . . . . 8 . . . . . . . . . .
 . . . . . . . . . . 9 8 . . 1 . 7 . . . .
 . . . . . . . . . . 2 . . . . . . . . . .
 . . . . . . . . 6 . 1 . . . 2 . . . . . .
 . . . . . 3 . . . . . . . . . . . . . . .
 . . . . . 4 . . . . . . . . . . . 2 . . .
 . . . . . . . . . . . . . . . . . 4 . 3 .
 . . . . . . . . . . . . . . . . . . . . .
 . . . . . . . . . . . . . . . . . . . . .
 . . . . . . . . . . . . . . . . . . . . .
 . 4 . 9 . . . . . . . . . . . . . . . . .
 . . . 2 . . . . . . . . . . . 5 . . . . .
 . . . . . . . . . . . . . . . 4 . . . . .
 . . . . . . 1 . . . 4 . 5 . . . . . . . .
 . . . . . . . . . . 1 . . . . . . . . . .
 . . . . 7 . 5 . . 5 6 . . . . . . . . . .
 . . . . . . . . . . 8 . . . . . . . . . .
 . . . . . . . . . . 7 . 2 . . . . 6 . . .
 . . . . . . . . . . . . . . . . . . . . .

 Number of clues  34 

.........9....3.4........8........98.......2......6.1...3........4............... TL
..1.7...............2....................2........4.3............................ TR
................................................................................. M
............................4.9........2....................1...............7.5.. BL
...............5........4...4.5......1.......56........8........7.2....6......... BR



[tarek]

images of m_b_metcalf's puzzles courtesy of Jsudoku (can be linked to through imgur)





The last 2 are intended for players to solve. The 1st one is the 1st posted ... too much effort went to bring this one to light, so it can't be forgotten (it is an extreme/impossible puzzle though)

tarek