The New Sudoku Players' Forum

[angusj]

When Simple Sudoku says
that a puzzle is assymetrical what does it mean?

It means the starting givens are not placed symetrically.

This isn't a problem (apart from a very minor aesthetic one) but it's a warning so you'll double check the puzzle you've entered manually in case you've made a mistake (since the majority of puzzles are symmetrical).

[CathyW]

It looks like single digit multi-coloring to me. Instead of being 5-sided turbot fish with 2 strong links (connected by a weak link), this one is 7-sided with 3 strong links (alternately connected by two weak links).

Ah - so I was correct in thinking that multi-colouring on 6s would lead to the same elimination in r4c3, but I didn't pick up the third conjugate pair in column 8.

Perhaps we need a third pair of colours to utilise in Simple Sudoku!

[ronk]

so I was correct in thinking that multi-colouring on 6s would lead to the same elimination in r4c3, but I didn't pick up the third conjugate pair in column 8.

There are actually 4 strong chains (albeit some with only 1 link) of conjugates, but only 3 are required to make an elimination.

Perhaps we need a third pair of colours to utilise in Simple Sudoku!

I suggest this workaround. Scan in order rows, cols, and boxes, coloring all cells in a strong chain with the same color. IOW initially disregard true/false parity. Then when you've zeroed in on a possible chain, re-color the true/false parity of that chain with the alternating colors of your choice. This might give you (enlargeable) images as follows:

xxxxxxxxxxxxxxxxxxxxxx

If the transition on a single grid is too confusing, just open a second Simple Sudoku window, cut and paste the puzzle, and then recolor in the 2nd window.

Ron

[CathyW]

Thanks Ron - that's a really helpful tip. Hopefully my attempts at multi-colouring will improve, i.e. ensure I pick up all the conjugate pairs. I find it a useful technique in harder puzzles that require something beyond, say, xy-wing.

[barbe rouge]

angusj,
lol, never crossed my mind to rotate the
puzzle to see the symmetry...
Thanks for everything and congruts for
the excellent program you have created

ronk,
thanks for the tip