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Impossible Menneske No. 04

 
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keith



Joined: 19 Sep 2005
Posts: 3150
Location: near Detroit, Michigan, USA

PostPosted: Sun Mar 03, 2013 5:09 pm    Post subject: Impossible Menneske No. 04 Reply with quote

Code:
 M6912021  Impossible (4283)
+-------+-------+-------+
| . . . | 7 . . | . . . |
| . . 1 | . 3 . | . . 2 |
| 5 . . | . . 6 | . . 1 |
+-------+-------+-------+
| . 9 . | . . 7 | 4 . . |
| . 1 3 | . . . | 7 2 . |
| . . 6 | . . . | . . . |
+-------+-------+-------+
| . 4 . | 3 6 . | . . 9 |
| . . 2 | . . . | . . . |
| . . . | . . 4 | . 5 . |
+-------+-------+-------+

Play this puzzle online at the Daily Sudoku site

Keith


Last edited by keith on Sun Mar 17, 2013 4:31 am; edited 1 time in total
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Marty R.



Joined: 12 Feb 2006
Posts: 5121
Location: Rochester, NY, USA

PostPosted: Sun Mar 03, 2013 5:25 pm    Post subject: Reply with quote

I usually play all your posted puzzles, but have to draw the line at this series. Embarassed Crying or Very sad Laughing
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keith



Joined: 19 Sep 2005
Posts: 3150
Location: near Detroit, Michigan, USA

PostPosted: Sun Mar 03, 2013 6:31 pm    Post subject: Reply with quote

Marty R. wrote:
I usually play all your posted puzzles, but have to draw the line at this series. Embarassed Crying or Very sad Laughing

I don't do these either, at least not in an armchair with pencil and paper! When I pick Menneskes, they are generally below 30. oaxen asked for really tough puzzles to discuss ...

Keith
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Marty R.



Joined: 12 Feb 2006
Posts: 5121
Location: Rochester, NY, USA

PostPosted: Sun Mar 03, 2013 6:55 pm    Post subject: Reply with quote

Quote:
oaxen asked for really tough puzzles to discuss ...


He got his wish. I tried the first two and it seemed fruitless to try more.
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JC Van Hay



Joined: 13 Jun 2010
Posts: 364
Location: Charleroi, Belgium

PostPosted: Sun Mar 03, 2013 8:56 pm    Post subject: Reply with quote

#1. r6c6=3;r56c1=4,r12c8=7=r7c13,r6c78=9; UP23
#2. Chain[3] : L2-Wing : 5r4c3=(5-7)r6c2=7r6c1-7r7c1=7r7c3 :=> -5r7c3;UP42;r89c7=6=r1c89,r2c12=67,r4c15=28,r9c345=289
#3. Chain[2] : EmptyRectangles on 8,9 : r3c3=r9c3-r9c45=r8c4 :=> -89r3c4;r3c4=4;r56c5=45
#4. Chain[8] : r9c3=9 or r1c1=9->contradiction :=> r9c3=8;UP81
Interpretation :
Code:
+------------------+-----------------+--------------------+
| 8-9(3)  (38)  4  | 7      1     2  | 589     68(9)  568 |
| 67      67    1  | 5      3     89 | 89      4      2   |
| 5       2     89 | 4      89    6  | 3       7      1   |
+------------------+-----------------+--------------------+
| 2(8)    9     5  | 16     (28)  7  | 4       16     3   |
| 48      1     3  | 689    45    89 | 7       2      568 |
| 2478    7(8)  6  | 8(12)  45    3  | 589(1)  8(19)  58  |
+------------------+-----------------+--------------------+
| 18      4     7  | 3      6     5  | 2       18     9   |
| 689     5     2  | 89     7     1  | 68      3      4   |
| 6(13)   6(3)  89 | 289    289   4  | 6(1)    5      7   |
+------------------+-----------------+--------------------+
Chain[8] : Kraken Row 1R6 -> 3r1c1=9r1c8 :=> -9r1c1

(1-2)r6c4=(2-8)r4c5=8r4c1-8r6c2=(8-3)r1c2=3r1c1
||
1r6c7-1r9c7=(1-3)r9c1=3r1c1
||
(1-9)r6c8=9r1c8

or
#4. Chain[3] : X-Loop on 8 : r4c1=r4c5-r3c5=r3c3-r1c2=r6c2 @ :=> -8r9c5.r156c1;r89c4=8
#5. Chain[2] : Skyscraper on 8 : r2c7=r2c6-r5c6=r5c9 :=> -8r1c9.r6c7;r56c9=8
#6. Chain[3] : S-Wing : 5r1c7=5r1c9-(5=8)r6c9-8r6c2=8r1c2 :=> -8r1c7
#7. Chain[4] : XY-Chain : (8=3)r1c2-(3=6)r9c2-(6=1)r9c7-(1=8)r7c8 :=> -8r1c8;UP81

[edit : correction of 2 typos]


Last edited by JC Van Hay on Tue Mar 05, 2013 7:03 am; edited 1 time in total
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oaxen



Joined: 10 Jul 2006
Posts: 96

PostPosted: Mon Mar 04, 2013 10:04 am    Post subject: Reply with quote

keith wrote:
Marty R. wrote:
I usually play all your posted puzzles, but have to draw the line at this series. Embarassed Crying or Very sad Laughing

I don't do these either, at least not in an armchair with pencil and paper! When I pick Menneskes, they are generally below 30. oaxen asked for really tough puzzles to discuss ...

Keith


And I am very happy you took the job to transfer them here. This time I failed so I have to ask my butler to print a new copy and recapitulate the pencilmarks. Then for sure I will enjoy it in my armchair.
Make a new try Marty! Find the promising bivalues and step after step you will be successful.
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DonM



Joined: 15 Sep 2009
Posts: 51

PostPosted: Tue Mar 05, 2013 2:30 am    Post subject: Reply with quote

Menneske Impossible 4 (ER=7.1) post SSTS (Simple Sudoku Technique Set):
Code:

 *-----------------------------------------------------------------------------*
 | 23689   2368    489     | 7       124589  12589   | 35689   34689   34568   |
 | 6789    678     1       | 4589    3       589     | 5689    46789   2       |
 | 5       2378    4789    | 2489    2489    6       | 389     34789   1       |
 |-------------------------+-------------------------+-------------------------|
 | 28      9       58      | 12568   1258    7       | 4       1368    3568    |
 | 48      1       3       | 45689   4589    589     | 7       2       568     |
 | 2478    2578    6       | 12458   12458   3       | 1589    189     58      |
 |-------------------------+-------------------------+-------------------------|
 | 178     4       578     | 3       6       1258    | 128     18      9       |
 | 13689   3568    2       | 1589    15789   1589    | 1368    13468   34678   |
 | 13689   368     89      | 1289    12789   4       | 12368   5       3678    |
 *-----------------------------------------------------------------------------*

1. (7)r7c3=r7c1-r6c1=(7-5)r6c2=(5)r7c2 => -5r7c3 -> many singles
Code:

 *--------------------------------------------------------------------*
 | 3689   368    4      | 7      1      2      | 5689   689    568    |
 | 6789   678    1      | 5      3      89     | 689    4      2      |
 | 5      2      89     | 489    489    6      | 3      7      1      |
 |----------------------+----------------------+----------------------|
 | 28     9      5      | 1268   28     7      | 4      168    3      |
 | 48     1      3      | 4689   4589   89     | 7      2      568    |
 | 2478   78     6      | 1248   2458   3      | 1589   189    58     |
 |----------------------+----------------------+----------------------|
 | 18     4      7      | 3      6      5      | 2      18     9      |
 | 689    5      2      | 89     7      1      | 68     3      4      |
 | 13689  368    89     | 289    289    4      | 168    5      7      |
 *--------------------------------------------------------------------*


2. SIS aur(36)r19c12[(6)r8c1=(6)r2c12]
(8)r3c3=r9c3-grp(8)r9c45=(8-9)r8c4=(9)r8c1-[(6)r8c1=(6)r2c12]-als(6=89)r2c67 => -8r2c12 -> (lc) -8r1c789
stte

This is one of those 'sheep in wolve's clothing' puzzles. Even after SSTS, there are still only 23 givens, but it largely crumbles after the first chain. There are many alternates to step #2, but the above was the only one I could find that totally finished it off without more basic methods being necessary.

Fun puzzle!
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keith



Joined: 19 Sep 2005
Posts: 3150
Location: near Detroit, Michigan, USA

PostPosted: Tue Mar 05, 2013 6:53 am    Post subject: Reply with quote

Quote:
Fun puzzle!


To each his own.

I hear oaxen's butler has been brewing many cups of tea!

Keith Very Happy
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JC Van Hay



Joined: 13 Jun 2010
Posts: 364
Location: Charleroi, Belgium

PostPosted: Tue Mar 05, 2013 7:50 am    Post subject: Reply with quote

DonM wrote:
2. SIS aur(36)r19c12[(6)r8c1=(6)r2c12] ... => -8r2c12 -> (lc) -8r1c789 stte
-8r2c12 is contained in the follow-on of step 1 (r89c7=6=r1c89,r2c12=67)!
But it doesn't imply -8r1c789 because of 8r3c3!

Nevertheless, +8r2c7 can be proved using a chain[7] after application of LS and LC from step 1.
Code:
+-----------------+----------------+---------------------+
| 8(39)  (38)  4  | 7     1     2  | 58(9)   68(9)  568  |
| 67     67    1  | 5     3     89 | 8-9     4      2    |
| 5      2     89 | 489   489   6  | 3       7      1    |
+-----------------+----------------+---------------------+
| 28     9     5  | 16    28    7  | 4       16     3    |
| 48     1     3  | 4689  4589  89 | 7       2      568  |
| 2478   7(8)  6  | 1248  2458  3  | (1589)  189    (58) |
+-----------------+----------------+---------------------+
| 18     4     7  | 3     6     5  | 2       18     9    |
| 689    5     2  | 89    7     1  | 68      3      4    |
| 6(13)  6(3)  89 | 289   289   4  | 6(1)    5      7    |
+-----------------+----------------+---------------------+
Chain[7] : 9r1c78=(9-3)r1c1=3r1c2-[3r9c2=(3-1)r9c1=1r9c7 and 8r1c2=58r6c29]-(158=9)r6c7 :=> -9r2c7;ste
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arkietech



Joined: 31 Jul 2008
Posts: 1708
Location: Northwest Arkansas USA

PostPosted: Thu Mar 07, 2013 4:18 am    Post subject: Reply with quote

I have been wanting to get into nets. Comments, help and advice welcomed.

Code:
 *-----------------------------------------------------------------------------*
 | 23689   2368    489     | 7       124589  12589   | 35689   34689   34568   |
 | 6789    678     1       | 4589    3       589     | 5689    46789   2       |
 | 5       2378    4789    | 2489    2489    6       | 389     34789   1       |
 |-------------------------+-------------------------+-------------------------|
 | 28      9       58      | 12568   1258    7       | 4       1368    3568    |
 | 48      1       3       | 45689   4589    589     | 7       2       568     |
 | 2478    2578    6       | 12458   12458   3       | 1589    189     58      |
 |-------------------------+-------------------------+-------------------------|
 | 178     4       578     | 3       6       1258    | 128     18      9       |
 | 13689   3568    2       | 1589    15789   1589    | 1368    13468   34678   |
 | 13689   368     89      | 1289    12789   4       | 12368   5       3678    |
 *-----------------------------------------------------------------------------*
net
7r3c3 7r6c2 5r4c3
7r7c3 5r4c3
5r4c3;
 
 *-----------------------------------------------------------*
 | 38-9  38    4     | 7     1     2     | 589   689   568   |
 | 67    67    1     | 5     3     89    | 89    4     2     |
 | 5     2     89    | 489   489   6     | 3     7     1     |
 |-------------------+-------------------+-------------------|
 | 28    9     5     | 16    28    7     | 4     16    3     |
 | 48    1     3     | 4689  4589  89    | 7     2     568   |
 | 2478  78    6     | 1248  2458  3     | 1589  189   58    |
 |-------------------+-------------------+-------------------|
 | 18    4     7     | 3     6     5     | 2     18    9     |
 | 689   5     2     | 89    7     1     | 68    3     4     |
 | 136   36    89    | 289   289   4     | 16    5     7     |
 *-----------------------------------------------------------*
net
9r1c1 8r3c3 8r6c2 8r4c5 8r9c4 8r2c6 8r8c7 1r7c8 1r9c1 -3r9c1
9r1c1 -3r1c1
contradiction -9r1c1; ste
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DonM



Joined: 15 Sep 2009
Posts: 51

PostPosted: Sat Mar 09, 2013 7:25 am    Post subject: Reply with quote

JC Van Hay wrote:
DonM wrote:
2. SIS aur(36)r19c12[(6)r8c1=(6)r2c12] ... => -8r2c12 -> (lc) -8r1c789 stte
-8r2c12 is contained in the follow-on of step 1 (r89c7=6=r1c89,r2c12=67)!
But it doesn't imply -8r1c789 because of 8r3c3!

Yes, another reason why I shouldn't do any solving after 10pm- that 8r3c3 (that prevents the locked candidates) couldn't be more obvious! Anyway, here is my revised solution. I was particularly interested in finding something that avoided other basic methods or all the various locked sets/candidates that seemed to follow what looked like good eliminations:

Menneske Impossible 4 (ER=7.1) post SSTS (Simple Sudoku Technique Set):
Code:
 
*-----------------------------------------------------------------------------*
 | 23689   2368    489     | 7       124589  12589   | 35689   34689   34568   |
 | 6789    678     1       | 4589    3       589     | 5689    46789   2       |
 | 5       2378    4789    | 2489    2489    6       | 389     34789   1       |
 |-------------------------+-------------------------+-------------------------|
 | 28      9       58      | 12568   1258    7       | 4       1368    3568    |
 | 48      1       3       | 45689   4589    589     | 7       2       568     |
 | 2478    2578    6       | 12458   12458   3       | 1589    189     58      |
 |-------------------------+-------------------------+-------------------------|
 | 178     4       578     | 3       6       1258    | 128     18      9       |
 | 13689   3568    2       | 1589    15789   1589    | 1368    13468   34678   |
 | 13689   368     89      | 1289    12789   4       | 12368   5       3678    |
 *-----------------------------------------------------------------------------*

1. (7)r7c3=r7c1-r6c1=(7-5)r6c2=(5)r7c2 => -5r7c3 -> many singles
2. als(1=68)r89c7-(68=9)r2c7-grp(9)r1c78=(9-3)r1c1=(3)r9c1 => -1r9c1 => several singles
3. aur(58)r16c79[(8)r2c7=(8)r5c9]-(6)r5c9=r4c8-(6=9)r1c8 => r2c7<>9=8
stte
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