- Code: Select all
`*-----------*`

|1..|...|..2|

|.9.|4..|.5.|

|..6|...|7..|

|---+---+---|

|.5.|9.3|...|

|...|.7.|...|

|...|85.|.4.|

|---+---+---|

|7..|...|6..|

|.3.|..9|.8.|

|..2|...|..1|

*-----------*

This puzzle (Easter Monster) doesn't have any symmetry.

There is no symmetry s such that for every clue c, s(c) is a clue.

But what is the "best" symmetry ?

Let's consider this isomorphic :

- Code: Select all
`*-----------*`

|..2|...|..1|

|.5.|..4|.9.|

|7..|...|6..|

|---+---+---|

|...|3.9|.5.|

|...|.7.|...|

|.4.|.58|...|

|---+---+---|

|6..|...|..7|

|.8.|9..|.3.|

|..1|...|2..|

*-----------*

If s is the anti-diagonal symmetry, then for every clue c (except r6c5) , s(c) is a clue of the puzzle.

Easter Monster has a symmetry modulo 1.

Finding by hand the best symmetry of a puzzle is an interesting but not easy exercice.

Here is tarek's Golden Nugget :

- Code: Select all
`*-----------*`

|...|...|.39|

|...|..1|..5|

|..3|.5.|8..|

|---+---+---|

|..8|.9.|..6|

|.7.|..2|...|

|1..|4..|...|

|---+---+---|

|..9|.8.|.5.|

|.2.|...|6..|

|4..|7..|...|

*-----------*

Are you able to find its "best" symmetry ?

What is the maximum value of a best symmetry ?

JPF