HoDoKu Solving Technique Index: Example for "Skyscraper"

Solving Technique Example

Original sudoku:

..1.....9.8.9...32..2173....2.............27..148..6......9........5..6319...7...

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

:0400:4:..1.+2+8+7+59.8+79.+5+132+9+52173+4+8+6.2.+7..+3+4....+5..27.+7148+3+26+9+5....9.+8+1+7.+7+8.5+1+96319..+87+5+2+4::414:

The following representation can be pasted in most Sudoku programs:

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

| 346    346  1   | 46    2    8   | 7  5  9  |

| 46     8    7   | 9     46   5   | 1  3  2  |

| 9      5    2   | 1     7    3   | 4  8  6  |

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

| 568    2    569 | 7     16   69  | 3  4  18 |

| 368    36   369 | 5     146  469 | 2  7  18 |

| 7      1    4   | 8     3    2   | 6  9  5  |

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

| 23456  346  356 | 2346  9    46  | 8  1  7  |

| 24     7    8   | 24    5    1   | 9  6  3  |

| 1      9    36  | 36    8    7   | 5  2  4  |

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

Representation of the step:

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

|  346    346  1   | -46     2    8   | 7  5  9  |

| *46     8    7   |  9     *46   5   | 1  3  2  |

|  9      5    2   |  1      7    3   | 4  8  6  |

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

|  568    2    569 |  7      16   69  | 3  4  18 |

|  368    36   369 |  5      146  469 | 2  7  18 |

|  7      1    4   |  8      3    2   | 6  9  5  |

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

|  23456  346  356 |  2346   9    46  | 8  1  7  |

| *24     7    8   | *24     5    1   | 9  6  3  |

|  1      9    36  |  36     8    7   | 5  2  4  |

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



Skyscraper: 4 in r2c5,r8c4 (connected by r28c1) => r1c4<>4