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sudocraz
Joined: 28 Apr 2008 Posts: 53
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Posted: Thu Jun 04, 2009 2:59 pm Post subject: Brain Basher June 2 |
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Hi All
Did anyone try the Brain Bashers Sudoku on June 2. My husband and I couldn't get anywhere with it. We don't know what we missed, but could only enter about 8 numbers in that puzzle. |
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Marty R.
Joined: 12 Feb 2006 Posts: 5770 Location: Rochester, NY, USA
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Posted: Thu Jun 04, 2009 3:58 pm Post subject: |
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I assume you mean the Super Hard. Here's a grid created hastily and I'm not sure if the basics are finished.
Code: |
+--------------+--------------+----------------+
| 279 129 3 | 159 6 8 | 4 179 157 |
| 679 8 1679 | 4 157 3 | 15679 2 157 |
| 5 4 1679 | 19 127 27 | 1679 3 8 |
+--------------+--------------+----------------+
| 249 7 129 | 8 1234 5 | 12 6 1234 |
| 3 125 1258 | 16 124 246 | 1278 147 9 |
| 24 6 128 | 7 1234 9 | 128 5 1234 |
+--------------+--------------+----------------+
| 1 259 2579 | 3 8 47 | 2579 479 6 |
| 679 3 5679 | 2 457 1 | 579 8 457 |
| 8 25 4 | 56 9 67 | 3 17 1257 |
+--------------+--------------+----------------+
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Play this puzzle online at the Daily Sudoku site |
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keith
Joined: 19 Sep 2005 Posts: 3355 Location: near Detroit, Michigan, USA
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Posted: Thu Jun 04, 2009 4:03 pm Post subject: |
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I assume you mean the "Super Hard": Code: | ..3.6.4..
.8.4.3.2.
5.......8
.7.8.5.6.
3.......9
.6.7.9.5.
1.......6
.3.2.1.8.
..4.9.3.. |
I did this one, but I think I used a different chain than in the last two steps below.
After basics: Code: | +-------------------+-------------------+-------------------+
| 279 129 3 | 159 6 8 | 4 179 157 |
| 679 8 1679 | 4 157 3 | 15679 2 157 |
| 5 4 1679 | 19 127 27 | 1679 3 8 |
+-------------------+-------------------+-------------------+
| 249 7 129 | 8 1234 5 | 12 6 1234 |
| 3 125 1258 | 16 124 246 | 1278 147 9 |
| 24 6 128 | 7 1234 9 | 128 5 1234 |
+-------------------+-------------------+-------------------+
| 1 259 2579 | 3 8 47 | 2579 479 6 |
| 679 3 5679 | 2 457 1 | 579 8 457 |
| 8 25 4 | 56 9 67 | 3 17 1257 |
+-------------------+-------------------+-------------------+
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Note: Highlight (select) white boxes to see the text
Hint 1:
Hint 2:
Hint 3:
Hint 4:
Hint 5:
By the way, when you ask Brain Basher to show you the solution, they actually explain it. Here's what they say for this one:
Quote: | R1C6 is the only square in row 1 that can be <8>
R3C8 is the only square in row 3 that can be <3>
R3C2 is the only square in row 3 that can be <4>
R9C1 is the only square in row 9 that can be <8>
R7C5 is the only square in row 7 that can be <8>
R7C4 is the only square in row 7 that can be <3>
Intersection of row 1 with block 1. The value <2> only appears in one or more of squares R1C1, R1C2 and R1C3 of row 1. These squares are the ones that intersect with block 1. Thus, the other (non-intersecting) squares of block 1 cannot contain this value.
R3C3 - removing <2> from <12679> leaving <1679>
Squares R5C6 and R7C6 in column 6 and R5C8 and R7C8 in column 8 form a Simple X-Wing pattern on possibility <4>. All other instances of this possibility in rows 5 and 7 can be removed.
R5C5 - removing <4> from <124> leaving <12>
Squares R1C2 and R7C2 in column 2 and R1C8 and R7C8 in column 8 form a Simple X-Wing pattern on possibility <9>. All other instances of this possibility in rows 1 and 7 can be removed.
R1C1 - removing <9> from <279> leaving <27>
R7C3 - removing <9> from <2579> leaving <257>
R1C4 - removing <9> from <159> leaving <15>
R7C7 - removing <9> from <2579> leaving <257>
R3C4 is the only square in column 4 that can be <9>
Squares R1C2 and R5C2 in column 2 and R1C4 and R5C4 in column 4 form a Simple X-Wing pattern on possibility <1>. All other instances of this possibility in rows 1 and 5 can be removed.
R5C3 - removing <1> from <1258> leaving <258>
R5C5 - removing <1> from <12> leaving <2>
R5C7 - removing <1> from <1278> leaving <278>
R1C8 - removing <1> from <179> leaving <79>
R5C8 - removing <1> from <147> leaving <47>
R1C9 - removing <1> from <157> leaving <57>
R3C6 is the only square in row 3 that can be <2>
R9C8 is the only square in column 8 that can be <1>
Intersection of column 6 with block 8. The value <7> only appears in one or more of squares R7C6, R8C6 and R9C6 of column 6. These squares are the ones that intersect with block 8. Thus, the other (non-intersecting) squares of block 8 cannot contain this value.
R8C5 - removing <7> from <457> leaving <45>
Squares R1C4 (XY), R3C5 (XZ) and R1C9 (YZ) form an XY-Wing pattern on <7>. All squares that are buddies of both the XZ and YZ squares cannot be <7>.
R3C7 - removing <7> from <167> leaving <16>
Squares R5C4 (XY), R5C2 (XZ) and R9C4 (YZ) form an XY-Wing pattern on <5>. All squares that are buddies of both the XZ and YZ squares cannot be <5>.
R9C2 - removing <5> from <25> leaving <2>
R1C1 is the only square in row 1 that can be <2>
R6C1 can only be <4>
R4C1 can only be <9>
R7C7 is the only square in row 7 that can be <2>
R4C7 can only be <1>
R4C3 can only be <2>
R3C7 can only be <6>
R6C7 can only be <8>
R5C7 can only be <7>
R6C3 can only be <1>
R5C8 can only be <4>
R5C6 can only be <6>
R4C9 can only be <3>
R6C5 can only be <3>
R3C3 can only be <7>
R5C2 can only be <5>
R6C9 can only be <2>
R4C5 can only be <4>
R3C5 can only be <1>
R7C3 can only be <5>
R2C1 can only be <6>
R1C4 can only be <5>
R8C5 can only be <5>
R5C3 can only be <8>
R7C2 can only be <9>
R5C4 can only be <1>
R9C6 can only be <7>
R7C8 can only be <7>
R1C2 can only be <1>
R8C3 can only be <6>
R7C6 can only be <4>
R1C8 can only be <9>
R9C9 can only be <5>
R8C1 can only be <7>
R2C3 can only be <9>
R8C7 can only be <9>
R8C9 can only be <4>
R2C5 can only be <7>
R9C4 can only be <6>
R2C7 can only be <5>
R1C9 can only be <7>
R2C9 can only be <1> |
Keith
Last edited by keith on Thu Jun 04, 2009 6:00 pm; edited 1 time in total |
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sudocraz
Joined: 28 Apr 2008 Posts: 53
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Posted: Thu Jun 04, 2009 4:53 pm Post subject: |
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Hi Keith & Marty
I did mean the superhard, forgot to mention that.
The quotes didn't come out so I am off to the BB site.
I always do paper and pencil, so I didn't get any hints.
Thanks for the tips |
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keith
Joined: 19 Sep 2005 Posts: 3355 Location: near Detroit, Michigan, USA
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Posted: Thu Jun 04, 2009 4:55 pm Post subject: |
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Here is, perhaps, a simpler solution.
The first X-wing takes out <4> in R5C5.
There is then a 4-cell chain (extended XY-wing, to some) 25, 56, 16, 12, that takes out <2> in R5C2.
That reveals an XY-wing 1-56 that solves R9C2, and the puzzle.
Keith |
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Marty R.
Joined: 12 Feb 2006 Posts: 5770 Location: Rochester, NY, USA
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Posted: Thu Jun 04, 2009 5:28 pm Post subject: |
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Quote: | The quotes didn't come out so I am off to the BB site. |
Sheila,
If you mean that you couldn't see what was within the quote, that's deliberate. Some people post solutions within the quote, then change the font color to white so people who don't want to see the answer won't see it. For those who want to see, just highlight (select) the text within the quote. |
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sudocraz
Joined: 28 Apr 2008 Posts: 53
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Posted: Thu Jun 04, 2009 5:37 pm Post subject: |
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Hi Marty,
Thanks for telling me about the white quotes. I didn't know that.
I went back to BB and got the answer. I can't believe that both my husband and I missed the X-Wing. Too many other numbers out there, I suppose.
This was a good puzzle. We will both rework it tonight. |
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storm_norm
Joined: 18 Oct 2007 Posts: 1741
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Posted: Thu Jun 04, 2009 6:19 pm Post subject: |
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for the chain gangers
after basics
Code: | .---------------------.---------------------.---------------------.
| 279 129 3 | 159 6 8 | 4 179 157 |
| 679 8 1679 | 4 157 3 | 15679 2 157 |
| 5 4 1679 | 19 127 27 | 1679 3 8 |
:---------------------+---------------------+---------------------:
| 249 7 129 | 8 1234 5 | 12 6 1234 |
| 3 125 1258 | 16 124 246 | 1278 147 9 |
| 24 6 128 | 7 1234 9 | 128 5 1234 |
:---------------------+---------------------+---------------------:
| 1 259 2579 | 3 8 47 | 2579 479 6 |
| 679 3 5679 | 2 457 1 | 579 8 457 |
| 8 25 4 | 56 9 67 | 3 17 1257 |
'---------------------'---------------------'---------------------' |
focus on column 9
and the marked cells
Code: | +-------+-------+----------+
| . . . | . . . | . . 157 |
| . . . | . . . | . . 157 |
| . . . | . . . | . . 8 |
+-------+-------+----------+
| . . . | . . . | . .*1234 |
| . . . | . . . | . . 9 |
| . . . | . . . | . .*1234 |
+-------+-------+----------+
| . . . | . . . | . . 6 |
| . . . | . . . | . .*457 |
| . . . | . . . | . . 1257 |
+-------+-------+----------+ |
notice that if the 4 is false in r8c9, then the hidden pair {3,4} is true in r46c9
this leads to the 2's in r46c9 to be false...etc... leads to
Code: | .---------------------.---------------------.---------------------.
| 279 129 3 | 159 6 8 | 4 179 157 |
| 679 8 1679 | 4 157 3 | 15679 2 157 |
| 5 4 1679 | 19 127 27 | 1679 3 8 |
:---------------------+---------------------+---------------------:
| 249 7 129 | 8 1234 5 |*12 6 *1234 |
| 3 125 1258 | 16 124 246 |*1278 147 9 |
| 24 6 128 | 7 1234 9 |*128 5 *1234 |
:---------------------+---------------------+---------------------:
| 1 259 2579 | 3 8 *47 |*2579 -479 6 |
| 679 3 5679 | 2 457 1 | 579 8 *457 |
| 8 *25 4 |*56 9 *67 | 3 17 *1257 |
'---------------------'---------------------'---------------------' |
hp= hidden pair
(4)r8c9 = (hp34-2)r46c9 = (2)r456c7 - (2)r7c7 = (2)r9c9 - (2=5)r9c2 - (5=6)r9c4 - (6=7)r9c6 - (7=4)r7c6; r7c8 <> 4
for a one stepper. |
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tlanglet
Joined: 17 Oct 2007 Posts: 2468 Location: Northern California Foothills
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Posted: Sat Jun 06, 2009 1:56 pm Post subject: |
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I followed the sequence of steps already posted by others with two additions, which apparently were not helpful in solving the puzzle.
After the initial x-wing on 4, I found a Kraken x-wing that deleted 5 from r8c9.
Then I noted both a x-wing 9 and a Kraken x-wing 9. The Kraken also deleted 9 in two of the cells that were deleted by the normal x-wing, but it also deleted the 9 in r3c3.
But then I still used the x-wing 1 and xy-wing (1-56) to complete the puzzle.
Ted |
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