HoDoKu Solving Technique Index: Example for "Doubly Linked ALS-XZ"

Solving Technique Example

Original sudoku:

.........2.....3495...3926..9.........41...8....598..4..182...6......7....3..6...

Use the following line if you want to load the sudoku in HoDoKu:

:9001:1678:.........2.....3495...3926..9.........41..+98....598..4..182...6......7....3..6...:515 516:111 112 162 625 711 712 713 714 715 716 725 726 744 794 811 812 813:

The following representation can be pasted in most Sudoku programs:

.------------------------.--------------------.--------------------.

| 1346789  134678  6789  | 2467   14678  1247 | 158   157    1578  |

| 2        1678    678   | 67     15678  157  | 3     4      9     |

| 5        1478    78    | 47     3      9    | 2     6      178   |

:------------------------+--------------------+--------------------:

| 13678    9       25678 | 23467  467    2347 | 156   12357  12357 |

| 367      23567   4     | 1      67     237  | 9     8      2357  |

| 1367     12367   267   | 5      9      8    | 16    1237   4     |

:------------------------+--------------------+--------------------:

| 479      457     1     | 8      2      3457 | 45    359    6     |

| 4689     24568   25689 | 349    145    1345 | 7     12359  12358 |

| 4789     24578   3     | 479    1457   6    | 1458  1259   1258  |

'------------------------'--------------------'--------------------'

Representation of the step:

.--------------------------------.-------------------------.--------------------.

| -1346-7-89  -1346-7-8   6-7-89 |  246-7   146-78   124-7 | 158   157    1578  |

|  2          B1678      B678    | A67      15-6-78  15-7  | 3     4      9     |

|  5          B1478      B78     | A47      3        9     | 2     6      178   |

:--------------------------------+-------------------------+--------------------:

|  13678       9          25678  |  2346-7  467      2347  | 156   12357  12357 |

|  367         23567      4      |  1       67       237   | 9     8      2357  |

|  1367       -12367      267    |  5       9        8     | 16    1237   4     |

:--------------------------------+-------------------------+--------------------:

|  479         457        1      |  8       2        3457  | 45    359    6     |

|  4689        24568      25689  |  349     145      1345  | 7     12359  12358 |

|  4789        24578      3      |  4-79    1457     6     | 1458  1259   1258  |

'--------------------------------'-------------------------'--------------------'



Almost Locked Set XZ-Rule: A=r23c4 {467}, B=r2c23,r3c23 {14678}, X=4,6, Z=6 => r1c12,r6c2<>1, r2c5<>6, r1c123456,r2c56,r49c4<>7, r1c123<>8