The New Sudoku Players' Forum

[EnderGT]

I've managed to do almost all of his puzzles with the tools you guys have helped me learn, and now it seems his puzzles are getting harder. So that means it's time for me to learn the next trick...

I need you to find it for me and show me how to apply it

The original:

Code: Select all

 . . . | 5 . . | . . 2
 3 . 2 | . . . | . . 6
 . . . | 9 . 4 | 7 . .
-------+-------+-------
 4 . 3 | . . . | 8 . .
 . 9 . | . . . | . 3 .
 . . 6 | . . . | 2 . 4
-------+-------+-------
 . . 8 | 1 . 9 | . . .
 2 . . | . . . | 9 . 8
 6 . . | . . 7 | . . .


And where I'm stuck:

Code: Select all

  9       1478    147     |  5       36      36      |  14      148     2
  3       45      2       |  78      17      18      |  45      9       6
  158     6       15      |  9       2       4       |  7       158     3
--------------------------+--------------------------+--------------------------
  4       2       3       |  67      157     156     |  8       1567    9
  1578    9       157     |  4678    14567   2       |  16      3       157
  1578    1578    6       |  378     9       1358    |  2       157     4
--------------------------+--------------------------+--------------------------
  57      34      8       |  1       346     9       |  346     2       57
  2       1347    147     |  346     3456    356     |  9       1467    8
  6       1345    9       |  2       8       7       |  1345    145     15


Thanks in advance...

[tarek]

Possible solution path.

Code: Select all

*-----------------------------------------------------------------*
| 9      1478   147   | 5      36     36    | 14     148    2     |
| 3     *45     2     | 78     17     18    |*45     9      6     |
| 158    6      15    | 9      2      4     | 7      158    3     |
|---------------------+---------------------+---------------------|
| 4      2      3     | 67     157    156   | 8      1567   9     |
|%1578   9      15-7  | 4678   14567  2     | 16     3     %157   |
|%1578   1578   6     | 378    9      1358  | 2      157    4     |
|---------------------+---------------------+---------------------|
|%57     34     8     | 1      346    9     | 3-46   2     %57    |
| 2      1347   147   | 346    3456   356   | 9      1467   8     |
| 6     *1345   9     | 2      8      7     |*1345  *145    15    |
*-----------------------------------------------------------------*
Eliminating 4 From r7c7 (Finned XWing(*) in r29 with 1 fin in Box 9)
Eliminating 7 From r5c3 (Finned XWing(%) in C19 with 1 fin in Box 4)
*-----------------------------------------------------------------*
| 9      1478   147   | 5      36     36    | 14     148    2     |
| 3     ^45     2     | 78     17     18    | 45     9      6     |
| 158    6     ^15    | 9      2      4     | 7      158    3     |
|---------------------+---------------------+---------------------|
| 4      2      3     | 67     157    156   | 8      1567   9     |
| 1578   9     -15    | 4678   14567  2     |%16     3      157   |
| 1578   1578   6     | 378    9      1358  | 2      157    4     |
|---------------------+---------------------+---------------------|
| 57    *34     8     | 1      346    9     |%36     2      57    |
| 2      1347   147   | 346    3456   356   | 9      1467   8     |
| 6      1345   9     | 2      8      7     | 1345   145    15    |
*-----------------------------------------------------------------*
Eliminating 1 from r5c3(ALS-XY  A(*)=34 in r7c2 B(%)=136 in r7c7,r5c7 C(^)=145 in r2c2,r3c3 x=3 y=4 z=1)

tarek

[Glyn]

Another possible is an Empty Rectangle which you could view as the Grouped AIC

(5)r46c8=(5)r5c9-(5)r5c3=(5)r3c3 => r3c8<>5, singles to follow.

[EnderGT]

Eliminating 4 From r7c7 (Finned XWing(*) in r29 with 1 fin in Box 9)
Eliminating 7 From r5c3 (Finned XWing(%) in C19 with 1 fin in Box 4)

Ah, yes, I see these now that you've pointed them out. Thanks.

Eliminating 1 from r5c3(ALS-XY A(*)=34 in r7c2 B(%)=136 in r7c7,r5c7 C(^)=145 in r2c2,r3c3 x=3 y=4 z=1)

And this I don't understand, so I guess I'll be doing some reading! Thanks again!

Edit: Ok, the more I look at this, the more I see that this is simply an XY-chain. with a different name. However, it should give me insight as to how to identify XY-chains in the future. Thanks!

[EnderGT]

Another possible is an Empty Rectangle which you could view as the Grouped AIC

(5)r46c8=(5)r5c9-(5)r5c3=(5)r3c3 => r3c8<>5, singles to follow.

I understand the Empty Rectangle concept, but Grouped AIC is new to me. More reading. Thanks!