Wednesday, September 11, 2013

Grille de la semaine #48 [League of Extraordinary Ladies and Gentlemen #35]

Un Figures Sudoku supplémentaire, en espérant que vous n'en êtes pas encore lassé(e)s. Je prends quant à moi toujours beaucoup de plaisir à explorer les possibilités offertes par cette variante.
Pour rappel, les grilles de la League sont jouables en ligne à l'adresse avec un délai de 24h.

More and more Figures Sudoku; I really like the type for the numerous possibilities it offers. Let's hope you are not tired of it yet.
Remember that you can solve the puzzles from the League online on with a 24h delay.

Règles :
Chaque ligne, colonne et région doivent contenir les chiffres de 1 à 9.
De plus, des zones pointillées de même forme doivent contenir les mêmes chiffres (mais pas nécessairement dans le même ordre).
Each row, column and region must contain the digits from 1 to 9.
Moreover, dotted areas with the same shape must contain the same set of digits (but not necessarily in the same order).

#55 Figures Sudoku


  1. Hi Bastien.A very nice sudoku.I have solved it. I was seeing how the top players had solved it on sudokucup.I could not understand some of the deductions that they made very early in the solve which i could get only rather deep into my solve.
    For example after the following steps
    i)19 in boxes 4&6
    ii)195 in boxes 3&7
    and then after a few more steps they deduced that 6 is in R3C4.6 can also be in R2C4 right (inside the figure)?Even after a deep thought i could not conclude how they could place that and similarly after placing 6 in R3C4 they narrowed down 5 to one of 2 cells R2C6/R3C6.5 may also be in R2C4 right?
    I would be very grateful if you could help me clear these logical blocks.

  2. Hi again. So, about putting a 6 in R3C4 (and similarly, a 4 in R7C6): actually, this can be done right at the beginning. You first need to notice the curious shape of the two dotted areas in the central vertical block (boxes 258); this shape was chosen on purpose, because I had a very precise idea of what I wanted to do here. Look at cells R4C4, R4C5 and R5C4: obviously, their content cannot be the same as the one of R5C6, R6C5 and R6C6, so, due to Figures Sudoku rule, they have to correspond to R7C5, R8C5 and R8C6. Also, R5C6, R6C5 and R6C6 correspond to R2C4, R2C5 and R3C4. If you followed me, you now know why R3C4 is the only cell that can accept a 6 in box 2, and R7C6 the only one convenient to the 4 in box 8 (and you can extend that to the 5).
    But there are more things you can deduce from these shapes. Look closely at R4C5: it has to contain the same digit as one of the cells from the second shape. Which one must it be? Now, using this combined with the 6 we put in box 2, you can find a third cell which content will have to be the same as the one of these two...