The New Sudoku Players' Forum

[m_b_metcalf]

Code: Select all

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

From the archive. Fairly hard.

[Edit: I now realise that I already posted this a long time ago. Sorry.]

[Mathimagics]

A Valentine gift, gee whiz, shucks!

Is "Hearts.doc" a printable form of the puzzle? I can't open that file - presumably it's a WORD document? ... but I have no Office products installed here

Guess I'll just have to knock up a Samurai printing facility ... that's long overdue in any case ...

[m_b_metcalf]

A Valentine gift, gee whiz, shucks!

Is "Hearts.doc" a printable form of the puzzle? I can't open that file - presumably it's a WORD document? ... but I have no Office products installed here

Guess I'll just have to knock up a Samurai printing facility ... that's long overdue in any case ...

Yes, yes, yes, and yes.

[Mathimagics]

I'll take that as a yes, then

[m_b_metcalf]

I'll take that as a yes, then

To make life easier for you, I've replaced the Word file by a PDF.

[1to9only]

Code: Select all

..4...9...6.8.2.1.2...3...74...9...39.......2.1.....8...8.....1...7.1.......2.5.. ED=1.5/1.2/1.2
..1...6...7.3.5.4.5...2...81...6...26.......5.4.....3.2.....1.....8.4.....8.5.... ED=1.5/1.2/1.2
..1...2.....5.4...5...7...88...2...77.......5.6.....4...4...1.....6.8.......5.... ED=1.7/1.2/1.2
..9.....4.6.8.4...5...1....1...4...59.......6.4.....1...3...2.....9.1.......7.... ED=6.6/1.2/1.2
1.....5.....1.9.2.....8...44...5...88.......9.2.....1...1...6.....4.2.......9.... ED=8.8/1.2/1.2


Solution:: Show

Code: Select all

834617925769852314251439867482196753976583142513274689328965471695741238147328596
321748659876395241594126378135467892687932415942581736253679184769814523418253967
471869253238514769596372418845123697713946825962785341354297186129638574687451932
819762354367854129524319687172648935935127846648593712793485261256931478481276593
186324597574169823932587164419756238867213459325948716791835642653472981248691375


[m_b_metcalf]

Code: Select all

..4...9...6.8.2.1.2...3...74...9...39.......2.1.....8...8.....1...7.1.......2.5.. ED=1.5/1.2/1.2
..1...6...7.3.5.4.5...2...81...6...26.......5.4.....3.2.....1.....8.4.....8.5.... ED=1.5/1.2/1.2
..1...2.....5.4...5...7...88...2...77.......5.6.....4...4...1.....6.8.......5.... ED=1.7/1.2/1.2
..9.....4.6.8.4...5...1....1...4...59.......6.4.....1...3...2.....9.1.......7.... ED=6.6/1.2/1.2
1.....5.....1.9.2.....8...44...5...88.......9.2.....1...1...6.....4.2.......9.... ED=8.8/1.2/1.2


Thanks for those ratings. The puzzle as published is not minimal. Here is a reduced, and thus harder, version:

Code: Select all

..4...9...6.8.2...2...3...74...9...39.......2.1.....8...8.........7.1.......2.5..  TL
..1...6...7.3.5.4.5...2...81...6...26.......5.4.....3.......1.....8.4.....8.5....  TR
..............4...5.......88...2...77.......5.......4.............6.8.......5....   M
..9.......6.8.4...5...1....1...4...59.......6.4.....1...3...2.....9.1.......7....  BL
......5.....1...2.....8...44...5...88.......9.2.....1...1...6.....4.2.......9....  BR



[1to9only]

Code: Select all

..4...9...6.8.2...2...3...74...9...39.......2.1.....8...8.........7.1.......2.5.. ED=9.1/1.2/1.2
..1...6...7.3.5.4.5...2...81...6...26.......5.4.....3.......1.....8.4.....8.5.... ED=9.3/1.2/1.2
..............4...5.......88...2...77.......5.......4.............6.8.......5.... ED=9.4/1.2/1.2
..9.......6.8.4...5...1....1...4...59.......6.4.....1...3...2.....9.1.......7.... ED=9.4/1.2/1.2
......5.....1...2.....8...44...5...88.......9.2.....1...1...6.....4.2.......9.... ED=9.5/1.2/1.2


[Hajime]

Code: Select all

..4...9...6.8.2...2...3...74...9...39.......2.1.....8...8.........7.1.......2.5.. ED=9.1/1.2/1.2
..1...6...7.3.5.4.5...2...81...6...26.......5.4.....3.......1.....8.4.....8.5.... ED=9.3/1.2/1.2
..............4...5.......88...2...77.......5.......4.............6.8.......5.... ED=9.4/1.2/1.2
..9.......6.8.4...5...1....1...4...59.......6.4.....1...3...2.....9.1.......7.... ED=9.4/1.2/1.2
......5.....1...2.....8...44...5...88.......9.2.....1...1...6.....4.2.......9.... ED=9.5/1.2/1.2


With Forcing Nets I get this with SiSeSuSo:

Code: Select all

Eliminated candidates per Method and per Sudoku

Method   \  Sudoku |   SER |     1     2     3     4     5
                   |-------|------------------------------
Not counted elims  |     0 |   121   113   144   131   105
Naked Singles      |   0.1 |    39    32    35    42    29
Hidden Singles     |   0.2 |    71    67    77    54    92
Naked Single  [1]  |   2.5 |     0     1     0     0     0
Naked Pair    [2]  |     3 |     2     8     4     4     0
Naked Triple  [3]  |   3.6 |     1     0     4     3     8
Naked Quad    [4]  |     5 |     0    11     0     3     1
Hidden Quad   [5]  |   5.4 |     0     2     4     0     0
Locked Singles[2]  |   2.8 |     8     6    20    21    24
WXYZ Wing     [4]  |   5.5 |     0     0     0     0     1
VWXYZ Wing    [5]  |   6.3 |     0     0     0     0     1
Turbot-fish   [4]  |   4.2 |     2     0     3     4     1
XY-Wing       [3]  |   4.1 |     0     0     0     2     0
XY-chain     [11]  |   7.3 |     0     0     0     0     1
Forcing Nets  [2]  |   9.2 |     0     0     3     1     3
Forcing Nets  [3]  |   9.3 |     1     1     1     1     0
                   |-------|------------------------------
Eliminated Cand's  |  1313 |   245   241   295   266   266
Sum(SER * Cand's)  | 703.5 |  67.8   135 172.4 155.1 173.2

Initial Candidates :  1313
Maximum SER rating :   9.3 - Approach
Labour rating      : 703.5 - Experimental rating
Guesses (BF/BT;FN) :   394
Time needed        : 00:00:07.467

The number [x] after a method indicates the number of cells involved or length of a chain.
In the table all eliminated candidates are counted per method and per Sudoku.

For Forcing Nets [x] means the the number of candidates of the starting cell that leads to a contradiction.
So the 3rd and 5th Sudoku have 3 bivalue cells that lead to a contradiction.
Sudoku 1 to 4 have all 1 trivalue cell that leads to a contradiction.
The numbers in the table are not eliminated candidates but involved cells.

I cannot find the SER/ED rating for Forcing Nets. So I assumed: 9.0 + (#candidates)/10
Can anyone provide a link to SER/ED rating for Forcing Nets?

[m_b_metcalf]

[Withdrawn]

[Hajime]

Here's a further reduced version, but I can't quite guarantee that it has a unique solution. Grateful for confirmation.

Code: Select all

..4...9...6.8.2...2...3...74...9...39.......2.1.....8...8.........7.1.......2.5..  TL
..1...6...7.3.5...5...2...81...6....6.......5.4.....3.......1.....8.4.....8.5....  TR
..............4...5.......8....2...77.......5.......4.............6.8.......5....   M
..9.......6.8.4...5...1....1...4...59.......6.4.....1...3...2.....9.1.......7....  BL
......5.....1...2.....8...44...5...88.......9.2.....1...1...6.....4.2.......9....  BR

I cannot solve it with logical methods, but with BruteForce/BackTrack it has many solutions.
But about the heart template: grid1,2 has no given in r2c8 and g5 no given in r2c6. Middle grid 3 is not symmetrical. OK?

[m_b_metcalf]

I cannot solve it with logical methods, but with BruteForce/BackTrack it has many solutions.
But about the heart template: grid1,2 has no given in r2c8 and g5 no given in r2c6. OK?

Thanks. Back to the drawing board.

Yes, you're right about the missing givens.

Thanks,

Mike