nightmare 10/19/06
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- New kid on the Grid
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- Joined: Wed Oct 25, 2006 5:42 pm
nightmare 10/19/06
help me solve the nightmare. i cant find a way to solve it using logic, and i need to to prove someone wrong...
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- New kid on the Grid
- Posts: 3
- Joined: Wed Oct 25, 2006 5:42 pm
hi Tom,
I can give you an answer to your question regarding this particular Nightmare, but that does not prove that every sudoku has a completely logical solution. We only know that all known sudokus have a logical solution.
Here is the solving path for the October 19 Nightmare:
Explanations for these techniques can be found in the solving guide on the main website.
Ruud
I can give you an answer to your question regarding this particular Nightmare, but that does not prove that every sudoku has a completely logical solution. We only know that all known sudokus have a logical solution.
Here is the solving path for the October 19 Nightmare:
Code: Select all
Digit 9 is a hidden single for r2c9 in multiple houses
Hidden single in column 1 for digit 9
Box 2 only has candidates for digit 7 in row 1
Naked Pair in box 7 for digits (7,8)
Naked single for digit 6 in r9c1
Hidden Pair in row 2 for digits (4,7)
Hidden Pair in column 8 for digits (3,7)
Cells r2c8 and r2c5 trigger an Empty Rectangle in Box 6 Digit 6.
Two Almost Locked Sets sharing digit 1 eliminate candidate(s) for digit 4
The first ALS r5c1 r5c3 r5c5 r5c7 v12348 shares digit 1 with r6c8 v14. All cells that can see all digits 4 in both sets are eliminated.
Hidden single in column 9 for digit 4
Hidden Pair in row 6 for digits (1,4)
Empty Rectangle found in Box 7 Digit 8
Finned Jellyfish found for digit 8
3D Medusa Coloring. Targets can see both end colors of 2 bridged clusters.
An XY-Chain links r8c9 and r5c7 for digit 1
Hidden single in column 7 for digit 1
Digit 1 is a hidden single for r6c6 in multiple houses
Row 6 has one empty cell for the final digit 4
Hidden single in box 6 for digit 2
Box 6 has one empty cell for the final digit 6
Digit 2 is a hidden single for r2c7 in multiple houses
Column 7 has one empty cell for the final digit 5
An XY-Chain links r5c5 and r8c2 for digit 2
Hidden single in row 8 for digit 2
Column 2 has one empty cell for the final digit 1
Digit 1 is a hidden single for r8c9 in multiple houses
Column 9 has one empty cell for the final digit 8
Box 9 has one empty cell for the final digit 8
Last instance of digit 1 in r1c8
Hidden single in column 5 for digit 2
Box 5 only has candidates for digit 8 in row 4
Swordfish found in rows (2,5,8), columns (1,3,5) for digit 8
Naked single for digit 6 in r4c5
Hidden single in row 2 for digit 6
Column 8 has one empty cell for the final digit 5
r3c6 causes an XY-Wing eliminating Digit 5
From this point, the puzzle can be solved with singles only.
Ruud
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- New kid on the Grid
- Posts: 3
- Joined: Wed Oct 25, 2006 5:42 pm
nightmare
i get it up to here
p s - i get the empty rectangle technique from ur solving guide on this site, but couldn't find the application in this problem. can i get a diagram, cause i know that might help.
also, your beta program couldnt even get hidden singles when i tested it, so i think its got new bugs.
thanks for all ur help,
tom
you lost me on the empty rectangle, though. could you provide me with a lengthy explanation for this problem, please. i would very much appreciate that, and, i also very much appreciate the help uv given me so far. thx.Digit 9 is a hidden single for r2c9 in multiple houses
Hidden single in column 1 for digit 9
Box 2 only has candidates for digit 7 in row 1
Naked Pair in box 7 for digits (7,8)
Naked single for digit 6 in r9c1
Hidden Pair in row 2 for digits (4,7)
Hidden Pair in column 8 for digits (3,7)
p s - i get the empty rectangle technique from ur solving guide on this site, but couldn't find the application in this problem. can i get a diagram, cause i know that might help.
also, your beta program couldnt even get hidden singles when i tested it, so i think its got new bugs.
thanks for all ur help,
tom