HoDoKu Solving Technique Index: Example for "ALS Chain"

Solving Technique Example

Original sudoku:

......5....4.18.9.3...7...6.6.9.2...79..8..43.............94.81..1..56...........

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

:9003:3:......5....4.18.9.3...7+9..6.6.9.2...79+5.8.+243.......+6...+6.94.81..1..56......+6....:213 813 219 719 137 747 148 362 164 564 166 767 769 772 281 282 289 591 592 293 393 893 397 797 798 799:384 394:

The following representation can be pasted in most Sudoku programs:

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

| 12689  1278   79  | 2346   234  36  | 5    1237  48   |

| 256    257    4   | 2356   1    8   | 37   9     27   |

| 3      1258   28  | 245    7    9   | 48   12    6    |

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

| 148    6      38  | 9      345  2   | 18   57    578  |

| 7      9      5   | 16     8    16  | 2    4     3    |

| 1248   1248   238 | 347    345  37  | 189  6     589  |

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

| 25     235    6   | 237    9    4   | 37   8     1    |

| 489    3478   1   | 2378   23   5   | 6    237   479  |

| 2489   23478  79  | 12378  6    137 | 49   235   2459 |

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

Representation of the step:

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

|  12689   1278   79  |  2346     234  36  |  5    1237   48   |

| A256    A257    4   | A2356     1    8   | B37   9     A27   |

|  3       1258   28  |  245      7    9   |  48   12     6    |

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

|  148     6      38  |  9        345  2   |  18   57     578  |

|  7       9      5   |  16       8    16  |  2    4      3    |

|  1248    1248   238 |  347      345  37  |  189  6      589  |

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

|  25      235    6   | D237      9    4   | C37   8      1    |

|  489     3478   1   |  2-378   D23   5   |  6    237    479  |

|  2489    23478  79  |  12-378   6    137 |  49   235    2459 |

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



Almost Locked Set Chain: 3- r2c1249 {23567} -7- r2c7 {37} -3- r7c7 {37} -7- r7c4,r8c5 {237} -3 => r89c4<>3