dailysudoku.com

[kdunk]

I am STUCK in the middle and unable to make a logical move.
There is no logical solution to solve this puzzle.

[someone_somewhere]

Hi,
Do you mean the following one?

- 5 - - 2 - 6 - -
2 - 7 - - - - 8 -
- 1 - 6 - - - - -
- - 1 8 - - 3 4 -
- - - 1 - 2 - - -
- 9 8 - - 6 1 - -
- - - - - 4 - 5 -
- 3 - - - - 8 - 7
- - 6 - 9 - - 3 -

6 in r2c2 8 in r5c9 - Unique Horizontal
2 in r4c2 9 in r4c6 - Unique in 3x3 block
4 not in r9c1, it is in r8c1 or r8c3 (Row on 3x3 Block interaction)
4 not in r9c2, it is in r8c1 or r8c3 (Row on 3x3 Block interaction)
4 in r5c2 - Unique Vertical
7 not in r7c1, it is in r7c2 or r9c2 (Column on 3x3 Block interaction)
7 not in r9c1, it is in r7c2 or r9c2 (Column on 3x3 Block interaction)
8 not in r7c1, it is in r7c2 or r9c2 (Column on 3x3 Block interaction)
8 not in r9c1, it is in r7c2 or r9c2 (Column on 3x3 Block interaction)
3 not in r1c4, it is in r1c6 or r2c6 or r3c6 (Column on 3x3 Block interaction)
3 not in r2c4, it is in r1c6 or r2c6 or r3c6 (Column on 3x3 Block interaction)
3 not in r2c5, it is in r1c6 or r2c6 or r3c6 (Column on 3x3 Block interaction)
3 not in r3c5, it is in r1c6 or r2c6 or r3c6 (Column on 3x3 Block interaction)
9 not in r7c1, Nacked Pair 2 9 in r7c3 and r7c7 (same Row)
2 not in r7c4, Nacked Pair 2 9 in r7c3 and r7c7 (same Row)
2 not in r7c9, Nacked Pair 2 9 in r7c3 and r7c7 (same Row)
9 not in r7c9, Nacked Pair 2 9 in r7c3 and r7c7 (same Row)
1 in r7c1 - Sole Candidate
6 in r7c9 5 in r9c1 - Sole Candidate
5 in r4c9 - Sole Candidate
7 in r4c5 2 in r6c9 - Sole Candidate
6 in r4c1 7 in r6c8 - Sole Candidate
9 in r5c7 3 in r6c1 - Sole Candidate
7 in r5c1 5 in r5c3 6 in r5c8 2 in r7c7 - Sole Candidate
3 in r5c5 9 in r7c3 4 in r9c7 - Sole Candidate
5 in r2c7 8 in r7c5 4 in r8c1 1 in r9c9 - Sole Candidate
7 in r3c7 7 in r7c2 2 in r8c3 9 in r8c8 7 in r9c6 - Sole Candidate
1 in r1c8 2 in r3c8 3 in r7c4 5 in r8c4 8 in r9c2 2 in r9c4 - Sole Candidate
4 in r6c4 1 in r8c6 - Sole Candidate
9 in r2c4 3 in r2c6 5 in r6c5 6 in r8c5 - Sole Candidate
7 in r1c4 8 in r1c6 4 in r2c9 4 in r3c5 - Sole Candidate
9 in r1c1 1 in r2c5 3 in r3c3 5 in r3c6 - Sole Candidate
4 in r1c3 3 in r1c9 8 in r3c1 9 in r3c9 - Sole Candidate

Final SuDoku Table

9 5 4 7 2 8 6 1 3
2 6 7 9 1 3 5 8 4
8 1 3 6 4 5 7 2 9
6 2 1 8 7 9 3 4 5
7 4 5 1 3 2 9 6 8
3 9 8 4 5 6 1 7 2
1 7 9 3 8 4 2 5 6
4 3 2 5 6 1 8 9 7
5 8 6 2 9 7 4 3 1

see u,

[Guest]

Hi there !

Just popping in to see how other people respond to the addictive side of those sudokus

This puzzle was definitely the toughest one imho (had to resort to the Hint! alternative which gave the extra 1)

[reliantrobin]

Hi someone_somewhere,

I also came up against a (logical) brick wall with this one so I tried to follow your solution. Perhaps I'm being slow, but I don't see the reason for:
"4 not in r9c1, it is in r8c1 or r8c3 (Row on 3x3 Block interaction) "
I have R8C1, R8C3, R9C1 and R9C2 as possibilities for a 4 in the bottom left 3x3 block. Why can I rule out R9?

[someone_somewhere]

hi,
Let me explain you what means "row on 3x3 block interaction":
take a look at row 8. We have to put a "4" in it.
It can not be in r8c4, r8c5 or r8c6 because of the "4" from r6c6.
It can not be in r8c8 becasue of the "4" from r4c8.

So, whats left for a "4" in row 8 is r8c1 or r8c3 !!!
Now we "Interact" this information from the row into the 3x3 block r6c1 to r9c3:
"4" must be in r8c1 or r8c3, so it can't be in r9c1 and not in r9c2.

see u,

[Guest]

It's easy when you know how!
Many thanks.

[someone_somewhere]

Hi,
Don't worry, I am also still learning . . .

BTW (By The Way) did you ever solved a Sudoku with 17 initial numbers?

see u,

[Max Beran]

Yes, 17-er quite possible. See "August 14 puzzle grade" thread for an example and see if you can work it through. I don't think it will present much of a problem so long as you don't clutter the board with lots of candidates.