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Clement
Joined: 24 Apr 2006 Posts: 1111 Location: Dar es Salaam Tanzania
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Posted: Fri Feb 25, 2022 8:12 pm Post subject: Evil 20220225 |
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Code: |
+-------+-------+-------+
| 4 . . | . . 7 | . . . |
| . . 3 | 1 . . | . . 4 |
| . . . | . 5 . | 1 7 . |
+-------+-------+-------+
| . 4 . | 5 . . | 9 . . |
| . . 5 | . 2 . | . 6 . |
| 6 . . | . . 9 | . . 8 |
+-------+-------+-------+
| . . 2 | 7 . . | . . 6 |
| . . . | . 3 5 | . 2 . |
| . 8 . | . . . | 3 . . |
+-------+-------+-------+
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Play this puzzle online at the Daily Sudoku site |
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TomC
Joined: 30 Oct 2020 Posts: 358 Location: Wales
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Posted: Sat Feb 26, 2022 10:01 am Post subject: |
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Thanks Clement, I took a very long time to get anywhere with this, but got there in the end!
Code: |
+-------------------+-------------------+-----------------+
| 4 12569 1689 | 23689 689 7 | 2568 3589 2359 |
| 25789 25679 3 | 1 689 268 | 2568 589 4 |
| 289 269 689 | 234689 5 23468 | 1 7 239 |
+-------------------+-------------------+-----------------+
| 12378 4 178 | 5 1678 1368 | 9 13 1237 |
| 13789 1379 5 | 348 2 1348 | 47 6 137 |
| 6 1237 17 | 34 147 9 | 2457 1345 8 |
+-------------------+-------------------+-----------------+
| 1359 1359 2 | 7 1489 148 | 458 14589 6 |
| 179 1679 14679 | 4689 3 5 | 478 2 179 |
| 1579 8 14679 | 2469 1469 1246 | 3 1459 1579 |
+-------------------+-------------------+-----------------+
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Quote: | You can remove the <8>'s in r138c4 ( and r4c56, r5c6 ) as this would give a <34> pair in box 5 which means that r3c6 would be <3> and <4> at the same time
So r5c4=8 and then fairly straitforward to finish |
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Mogulmeister
Joined: 03 May 2007 Posts: 1151
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Posted: Sun Feb 27, 2022 11:52 am Post subject: |
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Nice observation to a very intriguing puzzle, Tom. Thanks Clement.
Your <34> pair Tom, that is created by r5c4 < > 8, also creates a quad in box 2 <2689> which would leave r2c6 empty.
The ANP <348> is stark.
r56c4(8=34) is impossible so r56c4(34=8 ) is the solution.
Last edited by Mogulmeister on Mon Feb 28, 2022 8:54 am; edited 4 times in total |
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Mogulmeister
Joined: 03 May 2007 Posts: 1151
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Posted: Sun Feb 27, 2022 12:19 pm Post subject: |
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Which made me look at ALS possibilities:
Set A (Yellow) is {2,3,4,6,8,9}
Set B (Green) is {3,4)
Target cell (red) is r5c4
This is one of those very rare events (I have only seen it a handful of times) where there is more than one restricted common. We can make eliminations here using both 3 and 4 as the restricted common. So:
Restricted common 3 means we can eliminate 4 from r5c4 because it is seen by both 4's in Set A and Set B ie r3c4 and r6c4
Restricted common 4 means we can eliminate 3 from r5c4 because it is seen by all the 3's in Set A and Set B ie r136c4
This leaves just 8 in r5c4 |
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Clement
Joined: 24 Apr 2006 Posts: 1111 Location: Dar es Salaam Tanzania
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Posted: Wed Mar 02, 2022 4:30 pm Post subject: Evil 20220225 |
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Code: |
+-----------------------+--------------------------+----------------------+
| 4 12569 1689 | 2369-8 689 7 | 2568 3589 2359 |
| 25789 25679 3 | 1 689 268 | 2568 589 4 |
| 289 269 689 | b23469-8 5 c23468 | 1 7 239 |
+-----------------------+--------------------------+----------------------+
| 12378 4 178 | 5 167-8 d136-8 | 9 13 1237 |
| 13789 1379 5 |ea348 2 d134-8 | 47 6 137 |
| 6 1237 17 |ea34 147 9 | 2457 1345 8 |
+-----------------------+--------------------------+----------------------+
| 1359 1359 2 | 7 1489 148 | 458 14589 6 |
| 179 1679 14679 | 469-8 3 5 | 478 2 179 |
| 1579 8 14679 | 2469 1469 1246 | 3 1459 1579 |
+-----------------------+--------------------------+----------------------+
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Good solutions to TomC and Mogulmeister!
They can also be written as chain in compact form as
(8=3|4)56c4 – (4)r3c4 = (4-3)r3c6 = r45c6 – (3=8)r65c4 => - 8r138c4,r56c6,r5c6; lclste |
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Mogulmeister
Joined: 03 May 2007 Posts: 1151
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Posted: Thu Mar 03, 2022 7:31 am Post subject: |
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👍 Nice |
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