Everything about Sudoku that doesn't fit in one of the other sections


Postby Papy » Sat Jan 13, 2007 12:16 pm

How to detect quickly that to grids are not iso morph?

This method donesn't not say if they are isomorph it says thet they are not isomorph.

1- Two isomophs have always the same repartition of clues by box
for a block

If the first box have 2 clues, the second 5 and the last1 you can scrambe the grid , swap the digit. at end you still have a blockw'perhaps vertical) with the same clue repartition.
Not in the same colonnes, in yhe sme row , not with the same digit
but the same number

2- More speed: the repartition by box on all the grid is constan

If you have 4 clue box 1, 3 clue box 2, 3 3, 4 4, 1 5 ,6 6 ,0 7,8 8,6 9
You still have the same after swap, rotations or other

Bware iit's not because the repartition is tha same taht the grids are isomorph. The method id for detect no isomorph!

Programers use other way to c14 and detect isomorph but this method can be use with out computer.

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Joined: 15 August 2006

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