Multiple Solutions

[rakesh_rai]

Can someone tell briefly how to solve the "multiple solutions sudoku" of June 23? After complete pencilmarking, I had to use "trial and error" to get to the solution.

[gabriele]

Can someone tell briefly how to solve the "multiple solutions sudoku" of June 23? After complete pencilmarking, I had to use "trial and error" to get to the solution.

Rakesh, there is a mistake in the "to go" cells that shoul be 2
here the log from my solver
https://www.argio-logic.net/img/multiple.swf

note: the xcolors can be applied immediately from scratch with the same results

[purifire]

Gabriele, there seems to be an error in to To GO field for todays multiple. I have sent you an email with an attachment.

Rishi (purifire)

[gabriele]

Gabriele, there seems to be an error in to To GO field for todays multiple. I have sent you an email with an attachment.

Rishi (purifire)

Correct! 4 numbers can be inserted using coloring or chains techniques


when generating the puzzles I avoid to consider too complicated chains,
considering also complicated chains the numbers that can be placed are 10 (at least for my solver).

[Fred76]

In fact, creating these grids is complicated, because you have to be sure that, for each cell which doesn't require to be filled, there are at least 2 different digits from which a solution for the grid can be found.

I'm not sure if it is sufficient to find digits with known techniques. Perhaps there is a cell where only one digit is correct to have a valid solution, and cannot be found with chains (or other known techniques).

[gabriele]

In fact, creating these grids is complicated, because you have to be sure that, for each cell which doesn't require to be filled, there are at least 2 different digits from which a solution for the grid can be found.

I'm not sure if it is sufficient to find digits with known techniques. Perhaps there is a cell where only one digit is correct to have a valid solution, and cannot be found with chains (or other known techniques).

you're right, Fred.
Actually , I'm not sure that there are no other cells containing the same number in all the solutions.

I created the grids trying to avoid the use of complicated chains with many nodes.
I'm not completely satisfied of the results, perhaps i should reconsider the generation limiting the advanced techniques to Simple-Colors and XY-Chains.