The New Sudoku Players' Forum

[Audeoninja]

This is an expert level puzzle from an iPhone app, and I have double checked that all the small numbers are correct. This is the 3rd or 4th puzzle where i have put in all the small numbers and looked at it for about 20 minutes without finding anything. I've concluded that these puzzles are just computer generated and some of them are impossible, is there anything I'm missing to solve this?



Here is the link if the picture didn't work

This is my first time posting here so idk if used the image tags right

[JasonLion]

It is certainly solvable, though it appear to require chains. The next move I see, a type 2 unique rectangle, isn't too bad however. After that it gets a little more complex.

13.69.8546..5.8319589431267.5.3.91...9..1.53.3.1..5.9.218956..34657839219731..685

[denis_berthier]

It can be done with two bivalue-chains / AICs / Nice Loops (whichever name you give them)

biv-chain[3]: r6n6{c5 c9} - r5n6{c9 c3} - r5n4{c3 c6} ==> r6c5 <> 4
biv-chain[3]: r5n7{c1 c6} - b5n4{r5c6 r4c5} - r4c8{n4 n7} ==> r4c1 <> 7
Singles to the end

[ArkieTech]

Code: Select all

 *--------------------------------------------------*
 | 1    3    27   | 6    9    27   | 8    5    4    |
 | 6    24   247  | 5    27   8    | 3    1    9    |
 | 5    8    9    | 4    3    1    | 2    6    7    |
 |----------------+----------------+----------------|
 |b78   5   b246  | 3   b467  9    | 1   b47   268  |
 |c78   9    26-4 | 28   1   c47   | 5    3    268  |
 | 3   a24   1    | 28   67-4 5    | 47   9    268  |
 |----------------+----------------+----------------|
 | 2    1    8    | 9    5    6    | 47   47   3    |
 | 4    6    5    | 7    8    3    | 9    2    1    |
 | 9    7    3    | 1    24   24   | 6    8    5    |
 *--------------------------------------------------*
(4=2)r6c2-(2=8)r4c1358-(8=4)r5c16 => -4r5c3,r6c5; ste

[pjb]

Code: Select all

1      3     e27     | 6      9     d27     | 8      5      4     
6      4-2    247    | 5      27     8      | 3      1      9     
5      8      9      | 4      3      1      | 2      6      7     
---------------------+----------------------+---------------------
78     5      46-2   | 3      467    9      | 1      47     268   
78     9     b46-2   | 28     1     c47     | 5      3      268   
3     a24     1      | 28     467    5      | 47     9      268   
---------------------+----------------------+---------------------
2      1      8      | 9      5      6      | 47     47     3     
4      6      5      | 7      8      3      | 9      2      1     
9      7      3      | 1      24     24     | 6      8      5     


(2=4) r6c2 - r5c3 = (4-7) r5c6 = r1c6 - (7=2) r1c3 => -2 r2c2, r45c3
Phil