The New Sudoku Players' Forum

[eleven]

Code: Select all

 +-------+-------+-------+
 | . . 1 | 2 . . | . . 3 |
 | . . . | . . 4 | 2 . . |
 | 5 . . | . . . | . 6 . |
 +-------+-------+-------+
 | 7 . . | 6 . . | . 1 . |
 | . . . | . 3 . | . . . |
 | . 8 . | . . 9 | . . 4 |
 +-------+-------+-------+
 | . 3 . | . . . | . . 6 |
 | . . 7 | 1 . . | . 2 . |
 | 4 . . | . . 7 | 5 . . |
 +-------+-------+-------+

[JC Van Hay]

Classical swordfish when the 3 solved cells for a digit are on a principal or secondary diagonal : {1R267} or {1C237} -> r7c7=1; stte

[eleven]

Oops, i did not spot that one. Well hidden.

[pjb]

Code: Select all

 689     4679    1      | 2      56789  568    | 4789   45789  3     
 3689    679     3689   | 35789 b156789 4      | 2      5789  a15789 
 5       2479    23489  | 3789   1789  c138    | 14789  6      1789   
------------------------+----------------------+---------------------
 7       2459    23459  | 6      2458   258    | 389    1      2589   
 1269   e124569  24569  | 4578   3     d1258   | 6789   5789   25789 
 1236    8       2356   | 57     1257   9      | 367    357    4     
------------------------+----------------------+---------------------
 1289    3       2589   | 4589   24589  258    | 14789  4789   6     
 689     569     7      | 1      45689  3568   | 3489   2      89     
 4      f1269    2689   | 389    2689   7      | 5      389    89-1   


More than one x-cycle of 1's here:
(1)r2c9 = r2c5 - r3c6 = r5c6 - r5c2 = r9c2 => -1, r9c9; stte

Phil

[Pat]

Code: Select all

 +-------+-------+-------+
 | . . 1 | 2 . . | . . 3 |
 | . . . | . . 4 | 2 . . |
 | 5 . . | . . . | . 6 . |
 +-------+-------+-------+
 | 7 . . | 6 . . | . 1 . |
 | . . . | . 3 . | . . . |
 | . 8 . | . . 9 | . . 4 |
 +-------+-------+-------+
 | . 3 . | . . . | . . 6 |
 | . . 7 | 1 . . | . 2 . |
 | 4 . . | . . 7 | 5 . . |
 +-------+-------+-------+


the puzzle you posted is rated 6.7 ( not 6.5 )

joel64 # 285 # 12

Code: Select all

..12....3.....42..5......6.7..6...1.....3.....8...9..4.3......6..71...2.4....75..

( and no SwordFish )

maybe JC Van Hay looked at the 6.5,
that would be

champagne # 285 # 61


Code: Select all

..12....3.....14..5......6.7..6...8.....9.....4...5..2.1......8..97...5.6....49..

[eleven]

Yes, 6.7, my typo (corrected). The swordfish is finned.

[pjb]

I'm getting confused here. This puzzle (..12....3.....42..5......6.7..6...1.....3.....8...9..4.3......6..71...2.4....75..) has the sashimi swordfish of 1s at r2c59, r6c15, r7c17 => -1 r3c7, r9c9, stte. Alternatively it can be viewed as an x-cycle: (1)r7c7 = r7c1 - r6c1 = r6c5 - r2c5 = r2c9 => -1 r3c7, r9c9. As I posted above, there is a second x-cycle solving the puzzle.

Phil

[Pat]

I'm getting confused here. This puzzle
(..12....3.....42..5......6.7..6...1.....3.....8...9..4.3......6..71...2.4....75..)
has the sashimi swordfish of 1s at r2c59, r6c15, r7c17
=> -1 r3c7,
stte

right. the rating 6.7 guarantees that the puzzle can't be solved by an (un-finned) SwordFish (rated 3.8) -- but the finned SwordFish does work.

(1) r267\c157 + fin r2c9
[ OR (1) c269\r359 + fin r2c9 ]
==> exclude 1 at r3c7