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ravel



Joined: 21 Apr 2006
Posts: 536

PostPosted: Tue Mar 11, 2008 3:59 pm    Post subject: Fresh meat Reply with quote

It seems, you are much faster with solving the puzzles, than i with finding new ones. This one i generated myself. I am looking forward to your solutions. Probably its a bit harder than the "another one", but hopefully more fun than serious challenge.
Code:
 +-------+-------+-------+
 | 7 . . | . 5 . | . . . |
 | . . 6 | 4 1 . | 8 . . |
 | . 8 . | . . 9 | . . . |
 +-------+-------+-------+
 | . 6 . | 9 . 4 | . . . |
 | 3 9 . | . 7 . | . . . |
 | . . 1 | 2 . 3 | 4 . . |
 +-------+-------+-------+
 | . 3 . | . . 2 | . 6 . |
 | . . . | . . . | 1 5 . |
 | . . . | . . . | . . 9 |
 +-------+-------+-------+
>>> play online
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storm_norm



Joined: 18 Oct 2007
Posts: 1741

PostPosted: Tue Mar 11, 2008 6:38 pm    Post subject: Reply with quote

Code:
7      14     23     | 368    5      68     | 9      124    1246
9      25     6      | 4      1      7      | 8      23     235
14     8      35     | 36     2      9      | 56     147    147
------------------------------------------------------------------
A25    6      257    | 9      8      4      |A35     137    1357
3      9      4      |B15     7     B15     | 26     28     268
8      57     1      | 2      6      3      | 4      9      57
------------------------------------------------------------------
145    3      589    | 158    49     2      | 7      6      48
246    247    2789   | 678    349    68     | 1      5      2348
1-2456 12457  2578   |(15)678 34    B15     |A23     2348   9



I open the bidding...

with A = xy-wing {235} removes 2 from r9c1

and with B = UR {15} removes 1 and 5 from r9c4

then there is still an x-wing on 5 removing 5 from r9c2 and r4c9

leaves you with this grid...
Code:
7      14     23     | 368    5      68     | 9      124    1246
9      25     6      | 4      1      7      | 8      23     235
14     8      35     | 36     2      9      | 56     147    147
------------------------------------------------------------------
25     6      257    | 9      8      4      | 35     137    137
3      9      4      | 15     7      15     | 26     28     268
8      57     1      | 2      6      3      | 4      9      57
------------------------------------------------------------------
145    3      589    | 15     49     2      | 7      6      48
246    247    2789   | 678    349    68     | 1      5      2348
1456   1247   2578   | 678    34     15     | 23     2348   9
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storm_norm



Joined: 18 Oct 2007
Posts: 1741

PostPosted: Tue Mar 11, 2008 6:56 pm    Post subject: Reply with quote

Quote:
It seems, you are much faster with solving the puzzles, than i with finding new ones. This one i generated myself. I am looking forward to your solutions. Probably its a bit harder than the "another one", but hopefully more fun than serious challenge


was this puzzle meant for someone in particular??

it reads like you used "you" and "your" in the second person.
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storm_norm



Joined: 18 Oct 2007
Posts: 1741

PostPosted: Wed Mar 12, 2008 12:32 am    Post subject: Reply with quote

Code:
7      14     23     | 368    5      68     | 9      124    1246
9      25     6      | 4      1      7      | 8      23     235
14     8      35     | 36     2      9      | 56     147    147
------------------------------------------------------------------
2      6      57     | 9      8      4      | 35     17     137
3      9      4      | 15     7      15     | 26     28     268
8      57     1      | 2      6      3      | 4      9      57
------------------------------------------------------------------
145    3      89     | 15     49     2      | 7      6      48
46     247    2789   | 678    349    68     | 1      5      2348
1456   147    278    | 678    34     15     | 23     2348   9


this is the grid after 3 very long xy-chains
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Marty R.



Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA

PostPosted: Wed Mar 12, 2008 1:06 am    Post subject: Reply with quote

storm_norm wrote:
Code:
7      14     23     | 368    5      68     | 9      124    1246
9      25     6      | 4      1      7      | 8      23     235
14     8      35     | 36     2      9      | 56     147    147
------------------------------------------------------------------
2      6      57     | 9      8      4      | 35     17     137
3      9      4      | 15     7      15     | 26     28     268
8      57     1      | 2      6      3      | 4      9      57
------------------------------------------------------------------
145    3      89     | 15     49     2      | 7      6      48
46     247    2789   | 678    349    68     | 1      5      2348
1456   147    278    | 678    34     15     | 23     2348   9


this is the grid after 3 very long xy-chains

With regard to the 68 UR in boxes 2 and 8, either r1c4 must be = 3 or r8c4 must be = 7. Testing each reveals that the 3 in r1c4 completes the puzzle.
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Asellus



Joined: 05 Jun 2007
Posts: 865
Location: Sonoma County, CA, USA

PostPosted: Wed Mar 12, 2008 1:49 am    Post subject: Reply with quote

Interesting symmetry in those givens.


Beginning with the <5> X-Wing and the {15} UR mentioned by Norm as the first two steps, I ignore the XY Wing and proceed instead with a simple AIC in boxes 1 and 4 based on the strongly linked <5>s in c2.

[3] Eureka: (2)r4c3-(2)r1c3=(2-5)r2c2=(5-7)r6c2=(7-2)r4c3; r4c3<>2
Ordinary language: r1c3 is either 2 or not 2. r1c2 not 2 -> r2c2=2 -> r6c2=5 -> r4c3=7. In either case, r4c3 is not <2>.

This sets r4c1=2 and creates strongly linked <5>s in r79c1, leading to...

[4] 6-Cell {15} DP in boxes 5,7,8: r3c1=1.

The grid now:
Code:

+------------------+------------------+------------------+
| 7     4     23   | 368   5     68   | 9     12    126  |
| 9     25    6    | 4     1     7    | 8     23    235  |
| 1     8     35   | 36    2     9    | 56    47    47   |
+------------------+------------------+------------------+
| 2     6     57   | 9     8     4    | 35    137   137  |
| 3     9     4    | 5     7     1    | 26    28    268  |
| 8     57    1    | 2     6     3    | 4     9     57   |
+------------------+------------------+------------------+
| 5     3     89   | 1     49    2    | 7     6     48   |
| 46    27    2789 | 678   349   68   | 1     5     2348 |
| 46    1     278  | 678   34    5    | 23    2348  9    |
+------------------+------------------+------------------+


There is now a {68} UR that can remove <6> from r8c4. [Note: Reading Norm's subsequent post, I did not notice that the extra digits in this UR determine each other. I generally avoid testing extra digits in URs since if feels too much like forcing to me. But, it does solve the puzzle at this point.] And, there is another AIC in b789 very much like the one above that removes <4> from r8c9. But neither leads immediately to a solution. Instead, I did some Medusa multicoloring and found an AIC which does:

[5] Eureka:
(7-5)r4c3=(5-3)r4c7=(3)r9c7-(3=4)r9c5-(4)r9c8=(4-7)r3c8=(7)r4c8-(7)r4c3; r4c3<>7
Ordinary language:
r4c3=7 -> r4c7=5 -> r9c7=3 -> r9c5=4 -> r9c8 not 4 -> r3c8=4 -> r4c8=7. But, we cannot have two <7>s in r8. So, r4c3 is not <7>.
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ravel



Joined: 21 Apr 2006
Posts: 536

PostPosted: Tue Mar 18, 2008 9:11 am    Post subject: Reply with quote

Almost forgot to post the solution, i had prepared:

Code:
 *---------------------------------------------------------*
 | 7      14     23    | 368    5    68  | 9   124   1246  |
 | 9     X25     6     | 4      1    7   | 8   23   X235   |
 | 14     8      35    | 36     2    9   | 56  147   147   |
 |---------------------+-----------------+-----------------|
 |#25     6      257   | 9      8    4   |#35  137   13-57 |
 | 3      9      4     |@15     7   @15  | 26  28    268   |
 | 8     X57     1     | 2      6    3   | 4   9    X57    |
 |---------------------+-----------------+-----------------|
 | 145    3      589   | 158    49   2   | 7   6     48    |
 | 246    247    2789  | 678    349  68  | 1   5     2348  |
 | 1-2456 124-57 2578  |@678-15 34  @15  |#23  2348  9     |
 *---------------------------------------------------------*
x-wing 5 in r26c29 => r4c9<>5, r9c2<>5
xy-wing 235, Pivot r4c7 => r9c1<>2
UR 15 (type 1) in r59c46 => r9c4<>15
Code:
 *-------------------------------------------------------*
 | 7     14   *23    |#68+3   5   #68  | 9   124   1246  |
 | 9    *25    6     | 4      1    7   | 8   23    235   |
 | 14    8     35    | 36     2    9   | 56  147   147   |
 |-------------------+-----------------+-----------------|
 | 25    6     257   | 9      8    4   | 35  137   137   |
 | 3     9     4     | 15     7    15  | 26  28    268   |
 | 8    *57    1     | 2      6    3   | 4   9     57    |
 |-------------------+-----------------+-----------------|
 | 145   3     589   | 158    49   2   | 7   6     48    |
 | 246   24-7  2789  |#68+7   349 #68  | 1   5     2348  |
 | 1456  1247  2578  | 678    34   15  | 23  2348  9     |
 *-------------------------------------------------------*
UR 68: r1c4=3 or r8c4=7
r1c4=3 => r1c3=2 => r2c2=5 => r6c2=7
==> r6c2=7 or r8c4=7 => r8c2<>7
Remark: I understand, that Asellus does not like to test UR extra digits (in all directions) to get an elimination. But i cant resist, once i noticed them (and it does not take long time, also if i cant find something).
Code:
 *------------------------------------------------------*
 | 7     14     23    | 368  5    68  | 9   124   1246  |
 | 9     25     6     | 4    1    7   | 8   23    235   |
 | 14    8      35    | 36   2    9   | 56  147   147   |
 |--------------------+---------------+-----------------|
 | 25    6      257   | 9    8    4   | 35  137   137   |
 | 3     9      4     |#15   7   #15  | 26  28    268   |
 | 8     57     1     | 2    6    3   | 4   9     57    |
 |--------------------+---------------+-----------------|
 |#15+4  3      589   |#15   49   2   | 7   6     48    |
 |*246  *24    -2789  | 678  349  68  | 1   5     2348  |
 |#15+46 17-24 -2578  | 678  34  #15  | 23  2348  9     |
 *------------------------------------------------------*
DP 15 locks 46 to r79c1 => triple 246 in box 7 => r89c3<>2, r9c2<>24
Code:
 *--------------------------------------------------*
 | 7     14 @23   | 368  5    68  | 9   124   1246  |
 | 9    #25  6    | 4    1    7   | 8   23    235   |
 | 14    8   35   | 36   2    9   | 56  147   147   |
 |----------------+---------------+-----------------|
 |#25    6  @257  | 9    8    4   | 35  137   137   |
 | 3     9   4    | 15   7    15  | 26  28    268   |
 | 8    -57  1    | 2    6    3   | 4   9     57    |
 |----------------+---------------+-----------------|
 | 145   3   589  | 15   49   2   | 7   6     48    |
 | 246   24  789  | 678  349  68  | 1   5     348   |
 | 1456  17  578  | 678  34   15  | 23  2348  9     |
 *--------------------------------------------------*
w-wing 25 with strong link for 2 in column 3 (r2c2=5 or r4c1=5) => r6c2<>5
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