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July 30 H (???)

 
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supportd00d



Joined: 30 Jul 2008
Posts: 6

PostPosted: Wed Jul 30, 2008 5:28 pm    Post subject: July 30 H (???) Reply with quote

I can normally do the "Hard" puzzles without any hints, and if I do look at the hints I usually understand what I missed. But the hint 9 in r5c2 cannot be explained by the Dev interface, and I don't see the logic behind it.

can anyone explain it to me ??

Code:

+----------------+----------+--------------+
| 128  138  1238 | 9  4  7  | 5    138 6   |
| 9    3458 3458 | 6  1  58 | 2378 378 23  |
| 7    6    158  | 3  2  58 | 18   4   9   |
+----------------+----------+--------------+
| 6    2    48   | 5  38 9  | 347  37  1   |
| 18   189  7    | 4  38 2  | 6    359 35  |
| 3    459  45   | 7  6  1  | 49   2   8   |
+----------------+----------+--------------+
| 1258 7    1238 | 12 9  4  | 1238 6   235 |
| 4    18   6    | 12 5  3  | 1289 189 7   |
| 125  135  9    | 8  7  6  | 123  135 4   |
+----------------+----------+--------------+
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ravel



Joined: 21 Apr 2006
Posts: 536

PostPosted: Wed Jul 30, 2008 6:30 pm    Post subject: Reply with quote

Since in box 7 the 5 is locked to column 1, you can eliminate it from r9c2.
Help enough ?

Code:
 *-----------------------------------------------------------*
 | 128   138   1238  | 9     4     7     | 5     138   6     |
 | 9    #3458 #3458  | 6     1     58    | 2378  378   23    |
 | 7     6     158   | 3     2     58    | 18    4     9     |
 |-------------------+-------------------+-------------------|
 | 6     2     48    | 5     38    9     | 347   37    1     |
 | 18    189   7     | 4     38    2     | 6     359   35    |
 | 3    #459  #45    | 7     6     1     | 49    2     8     |
 |-------------------+-------------------+-------------------|
 | 1258  7     1238  | 12    9     4     | 1238  6     235   |
 | 4     18    6     | 12    5     3     | 1289  189   7     |
 | 125   135   9     | 8     7     6     | 123   135   4     |
 *-----------------------------------------------------------*
Alternatively to the basic moves there is a DP 45 in r26c23 with strong links for 4 in row 2 and column 2.
So 5 can be eliminated from r2c2 (UR type 6 or hidden UR) and (because locked in box1/c3 now) from r6c3.
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supportd00d



Joined: 30 Jul 2008
Posts: 6

PostPosted: Wed Jul 30, 2008 8:27 pm    Post subject: Reply with quote

ravel wrote:

Since in box 7 the 5 is locked to column 1, you can eliminate it from r9c2.
Help enough ?


Yes !!

I actually had seen that 5 was in col 1 in box 7, and had marked it down on my paper sheet (I only use play online when I get really stuck), but somehow I missed taking it out as a possibility in r9c2.

Then I see that 1,3 and 8 are the only numbers in r1c2 r8c2 and r9c2, thereby taking 1 and 8 out of r5c2, leaving just 9.

ravel wrote:

Alternatively to the basic moves there is a DP 45 in r26c23 with strong links for 4 in row 2 and column 2.
So 5 can be eliminated from r2c2 (UR type 6 or hidden UR) and (because locked in box1/c3 now) from r6c3.


I really don't understand this part !!!

Fortunately I didn't need to as your pointer made the rest of the puzzle fairly easy.

Thanks...
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eddieg



Joined: 12 Jan 2006
Posts: 47
Location: San Diego, CA USA

PostPosted: Wed Jul 30, 2008 10:54 pm    Post subject: Thanks for helping Reply with quote

I had issues with todays puzzle as well.
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sudocraz



Joined: 28 Apr 2008
Posts: 53

PostPosted: Thu Jul 31, 2008 5:24 pm    Post subject: Reply with quote

This is the hardest 'Hard' puzzle that I have seen. It is harder than many of the puzzles that are classed as 'Very Hard'.
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