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Clement
Joined: 24 Apr 2006 Posts: 1111 Location: Dar es Salaam Tanzania
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Posted: Mon Oct 15, 2018 6:27 pm Post subject: Daily Sudoku for 14-Oct-2018 - Extreme |
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Code: |
+-------+-------+-------+
| . . . | 7 3 4 | . . . |
| . 1 . | . . . | 9 4 . |
| 6 . . | . . . | . . 7 |
+-------+-------+-------+
| . . . | 4 . . | 8 5 . |
| 7 . 3 | . . . | 4 . 9 |
| . 6 8 | . . 5 | . . . |
+-------+-------+-------+
| 5 . . | . . . | . . 1 |
| . 9 6 | . . . | . 3 . |
| . . . | 5 9 6 | . . . |
+-------+-------+-------+
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Play this puzzle online at the Daily Sudoku site |
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immpy
Joined: 06 May 2017 Posts: 571
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Posted: Tue Oct 16, 2018 3:07 am Post subject: |
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Hello all.
After Basics: Code: |
+--------------+---------------+--------------+
| 29 8 259 | 7 3 4 | 1 6 25 |
| 23 1 7 | 268 2568 28 | 9 4 2358 |
| 6 34 245 | 128 1258 9 | 235 28 7 |
+--------------+---------------+--------------+
| 19 2 19 | 4 7 3 | 8 5 6 |
| 7 5 3 | 1268 1268 128 | 4 12 9 |
| 4 6 8 | 9 12 5 | 237 127 23 |
+--------------+---------------+--------------+
| 5 47 24 | 3 248 278 | 6 9 1 |
| 28 9 6 | 12 124 127 | 257 3 2458 |
| 1238 347 124 | 5 9 6 | 27 278 248 |
+--------------+---------------+--------------+
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Play this puzzle online at the Daily Sudoku site
There are various ways of attacking this one, but I liked what was an "almost" UR Type 6 on 12 in r56c58. Most likely it is merely a deadly pattern on 12. So I went with Paolo's method of finding a possible contradiction. If R5C8=1=>contradiction =>-1R5C8=>solution. A good following rinse leaves a Type 1 UR on 68 in r25c45, with the extra candidate of 5 in r2c5 (which can be placed). stte
cheers all, and great puzzle Clement...immp |
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immpy
Joined: 06 May 2017 Posts: 571
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Posted: Tue Oct 16, 2018 3:31 am Post subject: |
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Here is the grid after the good rinse:
Code: |
+----------+-----------+--------+
| 29 8 259 | 7 3 4 | 1 6 25 |
| 3 1 7 | 68 568 28 | 9 4 25 |
| 6 4 25 | 12 15 9 | 3 8 7 |
+----------+-----------+--------+
| 19 2 19 | 4 7 3 | 8 5 6 |
| 7 5 3 | 68 68 1 | 4 2 9 |
| 4 6 8 | 9 2 5 | 7 1 3 |
+----------+-----------+--------+
| 5 7 24 | 3 48 28 | 6 9 1 |
| 28 9 6 | 12 14 7 | 5 3 48 |
| 18 3 14 | 5 9 6 | 2 7 48 |
+----------+-----------+--------+
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Play this puzzle online at the Daily Sudoku site
This is where I used the Type 1 UR on 68 in r25c45. r2c5<>68(=5!). There is also a possible BUG+1 on 2 in r1c3, in which r1c3=2.
thanks again Clement...immp |
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Clement
Joined: 24 Apr 2006 Posts: 1111 Location: Dar es Salaam Tanzania
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Posted: Wed Oct 17, 2018 8:40 am Post subject: Daily Sudoku for 14-Oct-2018 - Extreme |
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Initial elimination using AIC leaves a UR like immpy Code: |
+---------------------+---------------------+---------------------+
| 29 8 f259 | 7 3 4 | 1 6 e25 |
| 23 1 7 | 268 2568 28 | 9 4 2358 |
| 6 ha4-3 g245 | 128 1258 9 |b235 28 7 |
+---------------------+---------------------+---------------------+
| 19 2 19 | 4 7 3 | 8 5 6 |
| 7 5 3 | 1268 1268 128 | 4 12 9 |
| 4 6 8 | 9 12 5 |c237 127 d23 |
+---------------------+---------------------+---------------------+
| 5 47 24 | 3 248 278 | 6 9 1 |
| 28 9 6 | 12 124 127 | 257 3 2458 |
| 1238 347 124 | 5 9 6 | 27 278 248 |
+---------------------+---------------------+---------------------+
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(4=3)r3c2 - r3c7 = r6c7 - (3=2)r6c9 - (2=5)r1c9 - r1c3 = (5-4)r3c3 = (4)r3c2 => - 3r3c2 leads to
Code: |
+------------------+-------------------+----------------+
| 29 8 259 | 7 3 4 | 1 6 25 |
| 3 1 7 |#68 #5-68 28 | 9 4 25 |
| 6 4 25 | 12 15 9 | 3 8 7 |
+------------------+-------------------+----------------+
| 19 2 19 | 4 7 3 | 8 5 6 |
| 7 5 3 |#68 #68 1 | 4 2 9 |
| 4 6 8 | 9 2 5 | 7 1 3 |
+------------------+-------------------+----------------+
| 5 7 24 | 3 48 28 | 6 9 1 |
| 28 9 6 | 12 14 7 | 5 3 48 |
| 18 3 14 | 5 9 6 | 2 7 48 |
+------------------+-------------------+----------------+
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Type 1 UR (68)r25c45 => - 68r2c5; stte |
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