Wednesday, February 28, 2007

Basic Sudoku techniques #3

Conceptual wise in solving sudoku, there is not much difference whether to first check across a row or downward a column.

Check across row and downward column after a new digit is inserted
The important point here is, checking must be down across and downward after a new digit is filled into a cell. By doing so, new hints may be discovered to help further solving of Sudoku.

Example:


Look at digit 5 in Box 2 and 5, each in Column D and E, this shows that the third digit 5 is possibly in Box 8, Cell F7or F8. Checking across Row 7 and 8, Row 8 is having digit 5 in Cell G8. We could conclude that digit 5 should be inserted into Cell F7.


There are times when there are two possible digits to a cell, which could not be certain yet at the moment. You could jot down the digits at upper right corner of the cell, meanwhile wait for more hints to come for solving the game.

More techniques will be shared in the next post.

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