Isolated Sudoku by Quadrata

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Isolated Sudoku by Quadrata

Postby HATMAN » Tue Feb 11, 2020 3:56 pm

Isolated Sudoku 3, 4 and 4H

David came up with this puzzle idea which he posted on the assassin site (among others). I've come up with a small presentation change to assist in making harder puzzles. I think that this Sudoku variant really has legs.

Each number in a box means that the adjacent four cells contain that number but do not contain its adjacent numbers. So for puzzle 3 in nonet 6 the bottom right box means that there is a 3 in r56c89 and r56c89 does not contain 2 or 4. If a box has no clues then it either has two pairs or four consecutive numbers.

By putting the isolated numbers in a box, then if the box is empty there are no isolated numbers. Whereas if there is no box no clue is given.

Isolated 3

I tried hard to find a puzzle with all the boxes and more than one solution. This one had two solutions so I used the given in r1c1 to lock it down.

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Isolated 4

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Isolated 4 Hard

4 and 4H are to demonstrate the value of having an empty box as a clue.

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Re: Isolated Sudoku by Quadrata

Postby HATMAN » Mon Mar 09, 2020 7:33 pm

Isodoku 17, 17H, 18 and 19

Continuing with Quadrata's Isolated Sudoku concept and making it harder:
The blue quadrants contain four unknown singletons.
The pink quadrants contain two pairs.
The red quadrants contain a sequence of four (while this is giving extra information it can be used to leave out other clues).
No quadrant means that no clue is given.

The puzzle numbers have built up as I've been knocking them up and printing them to use as "go to sleep" puzzles.

Isodoku 17

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Isodoku 17 Hard

A harder version

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Isodoku 18

Note this is AN and FNC if you want to make it very easy.

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Isodoku 19

This is NC. I suggest you solve it that way first and then without the constraint.

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HATMAN
 
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Re: Isolated Sudoku by Quadrata

Postby enxio27 » Sat Jun 20, 2020 6:17 pm

Trying to catch up with all I've missed in the past few months. This looks interesting, but I'm trying to wrap my head around the concept. I'll have to study it some more.
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