The New Sudoku Players' Forum

[Hajime]

As a spin-off from Mike's SamuraiPlus here an X-SamuraiPlus
9 Overlapping Sudokus, all with diagonals too. All overlapping boxes are clueless.

The light-blue boxes are part of 2 Sudoku's; the darker-blue are part of 4 Sudoku's.
1. It is a SingleOnly puzzle but not that easy.

Code: Select all

#9/X/B4/N4/H16/B28/N28/H4/B16/N16/H28/
92.817.......3....7.6.......1...8...89.47....4...................................
...435.68....1..........2.7...3...4.....79.52........3...........................
..............................3.5...............2.4..............................
...........................3........95.14.....4...9...5.9..........5....18.724...
...................................9....29.36...8...5.......7.5....9.......658.94
.............1........6................9.6.......................................
...........................5.68......3..2....1.86................................
................................98.1....7..9......47.2...........................
.......................................5.4................3........7.............


2. A medium puzzle with Pointing/Claiming , Turbot-fish (X-chains of 4 cells length) and some XY-Wings. SER~4.2

Code: Select all

#9/X/B4/N4/H16/B28/N28/H4/B16/N16/H28/
31...8.....7.9....8.............7...5.3.61...1.6.................................
...5...42....3.1..........9...8........97.4.6......9.7...........................
.................................................................................
...........................6.4......8.5.32........8...7..........9.7....46...3...
.................................8.1...28.9.7...5.............8....2.3.....8...75
....7................6.3.........................4...............................
....................................5.3.2........................................
........................................1.3.8....................................
...............................4.........................4.1................2....


3. A hard puzzle, SER>8.0

Code: Select all

#9/X/B4/N4/H16/B28/N28/H4/B16/N16/H28/
9...17.......3......6.......1...8...89..7....4...................................
...43...8....1..........2.....3...4.....7..52........3...........................
.................................................................................
...........................3........95..4.....4...9.....9..........5....1...24...
...................................9....2..36...8...5.......7......9.......65...4
.............1.........................9.6.......................................
...........................5..8......3.......1..6................................
................................9..1.......9......4..2...........................
.......................................5.4.........................7.............


All puzzles are symmetric.
In the code-strings first the Samurai is listed and than the Sohei-1.

[Pat]

1. SingleOnly

so i should use this to practice "singles"

but so many box-line interactions
just jump to my eyes
(while i miss some "singles")

[Hajime]

1. SingleOnly

so i should use this to practice "singles"

but so many box-line interactions
just jump to my eyes
(while i miss some "singles")

Yes, there is a solution path with Singles only:

• Naked single: a cell with only 1 candidate k left
• Hidden single: a house with only 1 candidate k left (in 1 of the cells)

But it is permitted to use additional methods, like box-line reduction, chains or kraken

[m_b_metcalf]

Hajime, well done on producing these puzzles. The first two solve easily, the last one will require more work on my side.

Mike

[creint]

1 0.1 s requiring naked singles makes it very hard because they are hard to find in large puzzles.
2 0.8 s requiring chains
3 9s requiring complex chains SE < 10. How fast was your solver with this one m_b_metcalf?

[m_b_metcalf]

1 0.1 s requiring naked singles makes it very hard because they are hard to find in large puzzles.
2 0.8 s requiring chains
3 9s requiring complex chains SE < 10. How fast was your solver with this one m_b_metcalf?

1 0.28s
2 1.59s
3 Work in progress

[m_b_metcalf]

I'm still working on #3, but as part of my testing I've produced what I think might be a minimal puzzle with SE>= 10 (from one of Hajime's grids). Maybe somebody could kindly check.

Thanks,

Mike

Code: Select all

 . . 9 . . . . . . 2 . . . . . . . . . . .
 . . . . . . . . . . . . . . . . . . . . .
 . . . . . . . 9 . . . . . . . 7 . . . 6 .
 . . . . . . . . . . . 5 . . . . . . . . .
 . . . . . . . . . . 3 . . . . . . . . . .
 . . . . . . . . . . 4 . . . . . . . . . .
 . . . . . . . . . . . . . . . . 9 . . 7 .
 . . . . . . . . . . . . . . . . . . . 9 .
 . . . . . . . . . . . . . . . . . . . . .
 . . 9 . . . . . . . . . . . . . . . . . .
 . . . . . . . . . . . . . . . . 1 . . . .
 . . . . . . 3 . . . . . . . . 5 . . 1 2 .
 . . . . . . . . . . . . . . . . 6 . . . .
 . . . . . . . . . . 7 . . . . . . . . . .
 . . . . . . . . . 8 . . . . . . . . . 8 .
 . . . . . . . . 8 . . . . 7 2 . . . . . .
 8 . . . 3 . . . . . . . . . 1 . . . . 3 .
 . . . 6 . . . . . . . . . 3 . . 1 7 . . .
 . . . . . . . . . . . . . . . . . . . . .
 . . . . . . 3 . . . . . . . . 7 2 . . . 6
 . . . . . . . . . . . . . 6 . . . . 2 . 5  39 clues, X-SamuraiPlus

[Hajime]

Maybe somebody could kindly check.

Do you have the puzzle code in 9 x 81 chars style?
I can work on it tomorrow.

[m_b_metcalf]

Maybe somebody could kindly check.

Do you have the puzzle code in 9 x 81 chars style?
I can work on it tomorrow.

Code: Select all

009000000000000000000000090000000000000000000000000000000000000000000000000000000
000000000000000000000700060000000000000000000000000000000090070000000090000000000
000000000000000000000000000000000000000000000300000000000000000000070000000800000
000000000000000000000000000000000008800030000000600000000000000000000300000000000
000060000000000000000000080072000000001000030030017000000000000000720006060000205
000200000000000000090000000000005000000030000000040000000000000000000000000000000
000000000000000000000000000009000000000000000000000300000000000000000000000000000
000090070000000090000000000000000000000010000000500120000060000000000000000000080
000000000000070000000800000008000072000000001000000030000000000300000000000000060

[creint]

Your 39 clues solved in 62 seconds, SE < 10.

Was not minimal this one is (31 clues):

Code: Select all

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

[m_b_metcalf]

Your 39 clues solved in 62 seconds, SE < 10.

Was not minimal this one is (31 clues):
[snip]

Please try this one, which takes me 8s to solve:

Code: Select all

..9....................3.9.2.....................................................
.1...........3.1....4..........265.....97..2..6...59.........7...............4...
.................................................................................
.4........9.......1...........7..1.....4.2....7....4..7..............3....2......
.......1.............1................1..............42.....1....................
.......1.....5.....9..1...4......................4..6............................
............................2..........................4........9.......1........
.......7...............4........69...........................1.............1.....
...........................1...4............14..............2..3.................

 . . 9 . . . . . . . . . . 1 . . . . . . .
 . . . . . . . . . . 5 . . . . . 3 . 1 . .
 . . . . . 3 . 9 . . 1 . . . 4 . . . . . .
 2 . . . . . . . . . . . . . . . 2 6 5 . .
 . . . . . . . . . . . . . . . 9 7 . . 2 .
 . . . . . . . . . . 4 . . 6 . . . 5 9 . .
 . . . . . . . . . . . . . . . . . . . 7 .
 . . . . . . . . . . . . . . . . . . . . .
 . . . . . . . . . . . . . . . . . 4 . . .
 . 2 . . . . . . . . . . . . . . . 6 9 . .
 . . . . . . . . . . . . . . . . . . . . .
 . . . . . . . . . . . . . . . . . . . . .
 . 4 . . . . . . . . . . . . . . . . . 1 .
 . 9 . . . . . . . . . . . . . . . . . . .
 1 . . . . . . . . . . . . . . 1 . . . . .
 . . . 7 . . 1 . . . 4 . . . . . . . . . .
 . . . 4 . 2 . . . . . . . . 1 . . . . . .
 . 7 . . . . 4 . . . . . . . . . . . . . 4
 7 . . . . . . . . . . . 2 . . . . . 1 . .
 . . . . . . 3 . . . . . . . . . . . . . .
 . . 2 . . . . . . . . . . . . . . . . . .  44 clues

[creint]

44 clues not minimal, 170 seconds SE < 10.
< 0.15 seconds with MiniSat.

[Hajime]

Code: Select all

1st  0.65 secs
2nd  12.9 secs (all methods ON)
3rd  53.4 secs
39c   5.6 secs
44c  22.3 secs

SiSeSuSo fastest strategy: All methods OFF, only naked/hidden singles and Forcing Nets ON, except the 2nd.
Cannot yet solve the 31c puzzle, because it has multiple solutions.
If I copied the puzzle correctly:

Code: Select all

. . 9 . . . . . . 2 . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . .
. . . . . . 9 . . . . . . . . 7 . . . 6 .
. . . . . . . . . . . 5 . . . . . . . . .
. . . . . . . . . . 3 . . . . . . . . . .
. . . . . . . . . . 4 . . . . . . . . . .
. . . . . . . . . . . . . . . . 9 . . 7 .
. . . . . . . . . . . . . . . . . . . 9 .
. . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . 1 . . . .
. . . . . . . . . . . . . . . 5 . . . 2 .
. . . . . . . . . . . . . . . . 6 . . . .
. . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . 8 . . . . . . . . . 8 .
. . . . . . . . 8 . . . . 7 . . . . . . .
8 . . . . . . . . . . . . . 1 . . . . 3 .
. . . 6 . . . . . . . . . 3 . . 1 7 . . .
. . . . . . . . . . . . . . . . . . . . .
. . . . . . 3 . . . . . . . . 7 2 . . . 6
. . . . . . . . . . . . . . . . . . 2 . .
                                         
#9/X/B4/N4/H16/B28/N28/H4/B16/N16/H28
..9.....................9........................................................
.....................7...6................................9..7........9..........
...........................................................................8.....
...................................88...........6....................3...........
....6....................8..7.........1....3..3..17...............72...6......2..
...2..............9.............5.......3........4...............................
.................................................................................
....9..7........9.......................1.......5...2.....6....................8.
.....................8.......8....7.........1.......3..........3.................


[creint]

You misplaced the 9 in grid 1 row 3. And its probably too hard for a logic solver.

[Hajime]

You misplaced the 9 in grid 1 row 3. And its probably too hard for a logic solver.

Oops. The 9 is misplaced. Corrected and indeed no solution found with logic and not even with Nested Forcing Nets .