HoDoKu Solving Technique Index: Example for "Locked Pair"

Solving Technique Example

Original sudoku:

8..21...7.4..891......4........98..5.9..3......7..14.9...........3...2542.......8

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

:0110:67:8..21..+47.4..891......4........98..5.9..3......7..14.9...........3...2542.......8::674 675 676 681 682 684 684 694 695 696 774 775 776 781 782 784 784 794 795 796:

The following representation can be pasted in most Sudoku programs:

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

| 8       356     569    | 2         1     356    | 3569   4      7   |

| 3567    4       256    | 3567      8     9      | 1      236    236 |

| 135679  123567  12569  | 3567      4     3567   | 35689  23689  236 |

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

| 1346    1236    1246   | 467       9     8      | 367    12367  5   |

| 1456    9       124568 | 4567      3     24567  | 678    12678  126 |

| 356     23568   7      | 56        256   1      | 4      2368   9   |

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

| 145679  15678   145689 | 13456789  2567  234567 | 3679   13679  136 |

| 1679    1678    3      | 16789     67    67     | 2      5      4   |

| 2       1567    14569  | 1345679   567   34567  | 3679   13679  8   |

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

Representation of the step:

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

| 8       356     569    | 2            1        356      | 3569   4      7   |

| 3567    4       256    | 3567         8        9        | 1      236    236 |

| 135679  123567  12569  | 3567         4        3567     | 35689  23689  236 |

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

| 1346    1236    1246   | 467          9        8        | 367    12367  5   |

| 1456    9       124568 | 4567         3        24567    | 678    12678  126 |

| 356     23568   7      | 56           256      1        | 4      2368   9   |

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

| 145679  15678   145689 | 1345-6-789   25-6-7   2345-6-7 | 3679   13679  136 |

| 1-6-79  1-6-78  3      | 1-6-789     *67      *67       | 2      5      4   |

| 2       1567    14569  | 1345-6-79    5-6-7    345-6-7  | 3679   13679  8   |

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



Locked Pair: 6,7 in r8c56 => r7c456,r8c124,r9c456<>6, r7c456,r8c124,r9c456<>7