An attempt to solve the puzzle in 6 steps with stte finish as follows:
- Code: Select all
+---------------------+-------------------+-------------------+
| 2 6 489-7 | 1 5 79 | 38 (4789) 3[7] |
| 3 79 179 | 2 8 4 | 16 6[7]9 5 |
| 14789 4579 145789 | 679 3 679 | 18 4[7]89 2 |
+---------------------+-------------------+-------------------+
| 5 8 [7]9 | 379 29 1 | 236 6[7] 4 |
| 6 1 3 | 47 24 5 | 28 [7]8 9 |
| 4[7]9 2 (479) | 36789 69 6789 | 5 (1) 3[7] |
+---------------------+-------------------+-------------------+
| 149 49 2 | 469 1469 3 | 7 5 8 |
| 1478 457 14578 | 48 14 2 | 9 3 6 |
| 89 3 6 | 5 7 89 | 4 2 1 |
+---------------------+-------------------+-------------------+
1) Grouped Empty Rectangle: ERI 7 @ b3r1c8 ERI 7 @ b6r6c8 ERI 7 @ b4r6c3 => -7 @ r1c3;
- Code: Select all
+----------------------+----------------------+---------------+
| 2 6 489 | 1 5 7(9) | 38 4789 37 |
| 3 79 179 | 2 8 4 | 16 679 5 |
| 1478-9 4579 145789 | 67(9) 3 (679) | 18 4789 2 |
+----------------------+----------------------+---------------+
| 5 8 79 | 379 29 1 | 236 67 4 |
| 6 1 3 | 47 24 5 | 28 78 9 |
| 479 2 479 | 36789 69 6789 | 5 1 37 |
+----------------------+----------------------+---------------+
| (149) 4(9) 2 | 46(9) 146(9) (3) | 7 5 8 |
| 1478 457 14578 | 48 14 2 | 9 3 6 |
| 8(9) 3 6 | 5 7 8(9) | 4 2 1 |
+----------------------+----------------------+---------------+
2) Grouped Empty Rectangle: ERI 9 @ b2r3c6 ERI 9 @ b8r7c6 ERI 9 @ b7r7c1 => -9 @ r3c1;
- Code: Select all
+--------------------+-------------------+---------------+
| 2 6 489 | 1 5 79 | 38 4789 37 |
| 3 79 179 | 2 8 4 | 16 679 5 |
| 1478 4579 145789 | 679 3 679 | 18 4789 2 |
+--------------------+-------------------+---------------+
| 5 8 (79) | 39-7 (29) 1 | 236 67 4 |
| 6 1 3 | (47) (24) 5 | 28 78 9 |
| 479 2 479 | 36789 69 6789 | 5 1 37 |
+--------------------+-------------------+---------------+
| 149 49 2 | 469 1469 3 | 7 5 8 |
| 1478 457 14578 | 48 14 2 | 9 3 6 |
| 89 3 6 | 5 7 89 | 4 2 1 |
+--------------------+-------------------+---------------+
3) WXYZ-Wing: 2479 @ r4c35 r5c45 => -7 @ r4c4;
- Code: Select all
+---------------------+-------------------+----------------+
| 2 6 489 | 1 5 79 | 38 4789 37 |
| 3 (7)9 1(7)9 | 2 8 4 | 16 6(7)9 5 |
| 1478 4579 14589-7 | 679 3 679 | 18 4789 2 |
+---------------------+-------------------+----------------+
| 5 8 (7)9 | 39 29 1 | 236 6(7) 4 |
| 6 1 3 | 47 24 5 | 28 78 9 |
| 479 2 479 | 36789 69 6789 | 5 1 37 |
+---------------------+-------------------+----------------+
| 149 49 2 | 469 1469 3 | 7 5 8 |
| 1478 457 14578 | 48 14 2 | 9 3 6 |
| 89 3 6 | 5 7 89 | 4 2 1 |
+---------------------+-------------------+----------------+
4) Grouped Skyscraper: Base Cells 7 @ r2c8 r4c8 Cover Cells 7 @ r2c23 r4c3 => -7 @ r3c3;
- Code: Select all
+-------------------+--------------------+---------------+
| 2 6 489 | 1 5 (79) | 38 4789 37 |
| 3 79 179 | 2 8 4 | 16 679 5 |
| 1478 4579 14589 | 69-7 3 679 | 18 4789 2 |
+-------------------+--------------------+---------------+
| 5 8 79 | 39 29 1 | 236 67 4 |
| 6 1 3 | (47) 24 5 | 28 78 9 |
| 479 2 479 | 36789 69 689-7 | 5 1 37 |
+-------------------+--------------------+---------------+
| 149 49 2 | 469 1469 3 | 7 5 8 |
| 1478 457 14578 | (48) 14 2 | 9 3 6 |
| 89 3 6 | 5 7 (89) | 4 2 1 |
+-------------------+--------------------+---------------+
5) Almost Locked Set move: 4789 @ r58c4 r19c6 => -7 @ r3c4 r6c6; and
- Code: Select all
+-------------------+---------------------+---------------+
| 2 6 489 | 1 5 79 | 38 4789 37 |
| 3 79 179 | 2 8 4 | 16 679 5 |
| 1478 4579 14589 | (69) 3 (6)79 | 18 4789 2 |
+-------------------+---------------------+---------------+
| 5 8 79 | 3-9 29 1 | 236 67 4 |
| 6 1 3 | 47 24 5 | 28 78 9 |
| 479 2 479 | 3678-9 (69) (6)89 | 5 1 37 |
+-------------------+---------------------+---------------+
| 149 49 2 | 469 1469 3 | 7 5 8 |
| 1478 457 14578 | 48 14 2 | 9 3 6 |
| 89 3 6 | 5 7 89 | 4 2 1 |
+-------------------+---------------------+---------------+
6) W-Wing: 69 @ r3c4 r6c5 SL between 6 @ r3c6 and 6 @ r6c6 => -9 @ r46c4; stte
Note: Not sure whether all 6 steps are necessary for stte finish or not. BTW, I am happy as long as the puzzle is solved without guessing.
R. Jamil------------
Penny wise; pound foolish.
Practice makes a man perfect.