Logic Masters Deutschland e.V.

Red and Blue

(Eingestellt am 19. Februar 2021, 18:41 Uhr von zetamath)

Normal sudoku rules apply.

To complete the puzzle, you must color all the uncolored squares red or blue.  The given colored squares are purple, and for all rules purposes, a purple square counts as both red and blue.  All purple cells are given.

Your coloring must satisfy all of the following:

1) The group of red squares is orthogonally connected.  The same is true of the group of blue squares.

2) No 2x2 region is either all red or all blue.  

3) The numbers on the rows indicate the sum of the red cells in that row.  The numbers in the columns give the sum of the blue cells in that column.

4) If a circled cell is red, it gives the number of red cells in its box.  If it is blue, it gives the number of blue cells in its box. 

To clarify, below is a completed grid (for a hypothetical puzzle) that satisfies all of the above rules:

The partial grid below includes many examples of things that are not allowed.

The things that are wrong are:

The red cells in row 1 do not sum to 22.

The red cells in row 2 do not sum to 21, because the purple cell is red, so they actually sum to 7+4+6+3+5=25

In box 1, there is a 2x2 all blue region (because the purple cell is also blue).

In box 2, the circled purple cell is both red and blue, so it should give the number of red cells, as well as the number of blue cells. The number of red cells is correct, it is 7. However, this box has only 3 blue cells, so the circled digit is wrong.

In box 3, the three red cells have been isolated from the other red cells, so the group of red cells is not orthogonally connected.

That's all, have fun, leave a comment if you enjoy the puzzle!

Play this puzzle online

Lösungscode: Row 3 followed by column 3

Zuletzt geändert am 19. Februar 2021, 19:13 Uhr

Gelöst von SirWoezel, Greg, Jesper, stefliew, harrison, polar, bigger, smckinley, vkolvekova, Ours brun, davidagg, sggrant89, MagnusJosefsson, PixelPlucker, henrypijames, Jaych, tinounou, panthchesh, NikolaZ, ibag, Mody, Vebby, juhish
Komplette Liste


am 4. Juni 2021, 12:36 Uhr von juhish
Wow! Fantastic and fun! Had to start over three times but finally solved it. I'm a big fan, looking forward to your next one!

Zuletzt geändert am 3. Mai 2021, 17:13 Uhr

am 3. Mai 2021, 16:30 Uhr von ibag
Nice puzzle, but not far as difficult as I expected, considering the rating.

Zuletzt geändert am 25. Februar 2021, 22:54 Uhr

am 25. Februar 2021, 17:17 Uhr von henrypijames
I've been staring at this one for days and can't find the entry. Maybe a small hint?

>> Here is a hint, passed through rot13: Gur svefg guvat lbh jvyy jnag gb qb vf pnyphyngr gur fhz bs gur checyr fdhnerf sebz gur tvira vasbezngvba.

<< Thx! Obviously the hint helped, but it was still very difficult even then.

am 20. Februar 2021, 12:06 Uhr von bigger
Nice and fun.

am 20. Februar 2021, 00:59 Uhr von Jesper
Very creative and challenging. Enjoyed it a lot.

am 20. Februar 2021, 00:45 Uhr von Greg
Very nice.

am 19. Februar 2021, 22:02 Uhr von SirWoezel
Great puzzle! Need to stay really focussed. Those pink squares are tricky buggers!

Zuletzt geändert am 19. Februar 2021, 19:24 Uhr

am 19. Februar 2021, 19:22 Uhr von kublai
Are all possible circles given? [Answer: No, not all possible circles are given.]

am 19. Februar 2021, 19:13 Uhr von zetamath
(It helps if I change it to the right fixed image)

am 19. Februar 2021, 19:10 Uhr von zetamath
Fixed a broken circle in the sample image.

Bewertung:96 %
Gelöst:23 mal
Beobachtet:1 mal


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