- Code: Select all
*-----------*
|...|1..|..2|
|.1.|.5.|...|
|..7|...|6..|
|---+---+---|
|5..|..2|...|
|.4.|.6.|.7.|
|...|5..|..1|
|---+---+---|
|..2|...|3..|
|...|.9.|.8.|
|3..|..1|...|
*-----------* # Nick70 puzzle presented recently by Ocean
# after basics
*-----------------------------------------------------------*
| 4689 689 489 | 1 3 7 | 489 5 2 |
| 2 1 3 | 489 5 6 | 7 49 489 |
| 489 5 7 | 489 2 48 | 6 1 3 |
|-------------------+-------------------+-------------------|
| 5 3 89 | 7 1 2 | 489 469 4689 |
| 89 4 1 | 3 6 89 | 2 7 5 |
| 7 2 6 | 5 48 489 | 89 3 1 |
|-------------------+-------------------+-------------------|
| 1 6789 2 | 468 478 5 | 3 469 4679 |
| 46 67 5 | 2 9 3 | 1 8 467 |
| 3 6789 489 | 468 478 1 | 5 2 4679 |
*-----------------------------------------------------------*
Consider the following forcing chains on [r6c7] and note the flipping action on <89> by the time each chain gets to [r1c7].
- Code: Select all
[r6c7]-8-[r6c56]=8=[r5c6]=9=[r5c1]-9-[r13c1]=9=[r1c23]-9-[r1c7] => [r1c7]<>8|9
[r6c7]-9-[r6c 6]=9=[r5c6]=8=[r5c1]-8-[r13c1]=8=[r1c23]-8-[r1c7] => [r1c7]<>8|9
Thus, [r1c7]=4 ... and a cascade of Singles solves the puzzle.
