Stumped.

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Stumped.

Postby QiGuy » Wed Jan 26, 2011 3:19 pm

I have tried this puzzle twice and get to the same point. Can't get any further. Can anyone help? Thx.
Code: Select all
128  7    126  4    569  3    569  68   258
249  249  3    126  8    15   7    46   245
248  5    246  26   69   7    3469 1    2348
5    24   24   3    1    6    8    7    9
6    1    9    5    7    8    34   2    34
7    3    8    9    2    4    1    5    6
134  6    145  8    35   2    45   9    7
39   89   7    16   4    15   2    368  58
234  248  245  7    356  9    456  3468 1
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Re: Stumped.

Postby QiGuy » Wed Jan 26, 2011 3:21 pm

Sorry for the jumble of numbers -- I pasted it in from Excel and it didn't take the spacing.
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Re: Stumped.

Postby JasonLion-Admin » Wed Jan 26, 2011 3:37 pm

I fixed up the formatting for you. The key step is to use a code tag around the fixed format text.

I see a unique rectangle.
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Re: Stumped.

Postby QiGuy » Wed Jan 26, 2011 7:36 pm

Wow! Is it r2c4, r2c6, r8c4, r8c6? In which case r2c4 must be 2?
I've never used that before; if I've got it right, I can see that it's very effective.
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Re: Stumped.

Postby QiGuy » Wed Jan 26, 2011 7:51 pm

No, I don't think I have identified the rectangle. May need some assistance here.
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Re: Stumped.

Postby JasonLion » Wed Jan 26, 2011 8:28 pm

A type 4 in R35C79 on 34.
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Re: Stumped.

Postby daj95376 » Wed Jan 26, 2011 9:16 pm

There's also a pair of X-Wings present. One is very productive, the other isn't.
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Re: Stumped.

Postby QiGuy » Wed Jan 26, 2011 9:38 pm

Is the effect of the unique rectangle, type 4, that because the 3 MUST be in r3c7 or r3c9, then the 4 can be in neither? Sorry to be thick about this, but I've not run into these before and I'm eager to pick up this technique.
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Re: Stumped.

Postby QiGuy » Wed Jan 26, 2011 9:41 pm

Also, daj95376, point out the productive X-wing and I'll see if I can find the other.
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Re: Stumped.

Postby JasonLion » Wed Jan 26, 2011 10:13 pm

Look at the digit 6 in rows 2 & 8.
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Re: Stumped.

Postby QiGuy » Thu Jan 27, 2011 1:58 pm

Got the X-Wing; thanks. Still confused about the rectangle.
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Re: Stumped.

Postby ronk » Thu Jan 27, 2011 2:31 pm

QiGuy wrote:Is the effect of the unique rectangle, type 4, that because the 3 MUST be in r3c7 or r3c9, then the 4 can be in neither? Sorry to be thick about this, but I've not run into these before and I'm eager to pick up this technique.

If digit 4 is ultimately placed in neither r3c1 nor r3c3, then r35c79 contains a deadly pattern -- in this case, candidates <34> in all four UR cells. The deadly pattern cannot occur in a puzzle with a unique solution. Therefore, ultimately either r3c1=4 or r3c3=4. All digit 4 candidates that see both these cells may be eliminated.
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Re: Stumped.

Postby QiGuy » Thu Jan 27, 2011 3:00 pm

Nice! Thanks very much -- got it!
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