Five steps (aware of DP from start, but I did not see how to use it soon).
After basics
- Code: Select all
,-----------------------------------------------------------,
| 7 6 24 | 459 149 1259 | 259 8 3 |
| 9 234 5 | 348 348 28 | 6 1 7 |
|(38) 1 (8)2 | 6 379 2579 | 259 4 59 |
|-------------------+-------------------+-------------------|
|(3)68 2349 1 | 4789 5 789 | 89 27-3 69 |
| 68 249 2478 | 1 4789 3 | 589 27 569 |
| 5 9-3 b(78) | 789 2 6 | 4 a(37) 1 |
|-------------------+-------------------+-------------------|
| 1 5 39 | 2 39 4 | 7 6 8 |
| 4 8 69 | 79 1679 179 | 3 5 2 |
| 2 7 36 | 358 368 58 | 1 9 4 |
'-----------------------------------------------------------'
1. (3=7)r6c6 - (7=8)r6c3 - (8)r3c3 = (8-3)r3c1 = (3)r4c1 => -3 r6c2, r4c8 [2 placements]
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- Code: Select all
,----------------------------------------------------------,
| 7 6 A[4]2 | 59-4 149 1259 | 259 8 3 |
| 9 234 5 |c(3)48 348 28 | 6 1 7 |
|e(38) 1 f8)2 | 6 d(3)79 2579 | 259 4 59 |
|------------------+----------------------+----------------|
| 368 234 1 |D[4]789 5 789 | 89 27 69 |
| 68 24 B[4]278| 1 C[4]79-8 3 | 589 27 569 |
| 5 9 g(8)7 |h(8)7 2 6 | 4 3 1 |
|------------------+----------------------+----------------|
| 1 5 39 | 2 39 4 | 7 6 8 |
| 4 8 69 | 79 1679 179 | 3 5 2 |
| 2 7 a(36) |b(3)5-8 a(368) 58 | 1 9 4 |
'----------------------------------------------------------'
2. (8=63)r9c35 - (3)r9c4 = r2c4 - r3c5 = (3-8)r3c1 = (8)r3c3 - (8)r6c3 = (8)r6c4 => -8 r5c5, r9c4
3. (4): r1c3 = r5c3 - r5c5 = r4c4 => -4 r1c4 (A..D)
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- Code: Select all
,-----------------------------------------------------------,
| 7 6 24 |*59 14-9 1259 | 259 8 3 |
| 9 234 5 | 348 348 28 | 6 1 7 |
| 38 1 28 | 6 37-9 2579 | 259 4 59 |
|-------------------+-------------------+-------------------|
| 368 234 1 | 4789 5 789 | 89 27 69 |
| 68 24 2478 | 1 479 3 | 589 27 569 |
| 5 9 78 | 78 2 6 | 4 3 1 |
|-------------------+-------------------+-------------------|
| 1 5 39 | 2 *39 4 | 7 6 8 |
| 4 8 69 | 7-9 1679 179 | 3 5 2 |
| 2 7 36 |*35 368 58 | 1 9 4 |
'-----------------------------------------------------------'
4. Y-wing (359)r19c4,r7c5 => -9 r13c5, r8c4 [3 placements]
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- Code: Select all
,--------------------------------------------------------------,
| 7 6 24 | 59 14 1259 | 259 8 3 |
| 9 234 5 |e(34) 348 28 | 6 1 7 |
| 38 1 28 | 6 37 2579 | 259 4 59 |
|-------------------+----------------------+-------------------|
| 368 234 1 |e(49) 5 7-9 | 89 27 69 |
| 68 24 248 | 1 479 3 | 589 27 569 |
| 5 9 7 | 8 2 6 | 4 3 1 |
|-------------------+----------------------+-------------------|
| 1 5 *39 | 2 *39 4 | 7 6 8 |
| 4 8 *69 | 7 b*69(1) a(19) | 3 5 2 |
| 2 7 *36 |d(35) c*36(8) d(58) | 1 9 4 |
'--------------------------------------------------------------'
5. DP (369)r789c35:
(9=1)r8c6 - (1)r8c5 == (8)r9c5 - (8=53)r9c46 - (3=49)r24c4 => -9 r4c6; ste