Double Dutch Sudoku Advent (6) - Clone vs. Edge Difference
(Published on 6. December 2014, 12:00 by Eisbär)
Richard and I have created a fresh sudoku advent calendar in which we combine a well known variant with a relatively unknown variant every day. Combining variants leads to interesting and surprising new solving techniques.
Logically solvable
All puzzles can be solved completely logically although the logic is sometimes well hidden and is inherent to the combination of restrictions that the different types offer. For that reason we have written some solving hints for most of the puzzles, published in a very tiny font. If you want to read the hints, simply copy these in a text editor and enlarge the font size.
Clone (Tetris)
Place the digits from 1 to 9 in every row, column and 3x3-block. The grid contains five different shapes. Each shape is cloned once. Cloned shapes may be rotated, but the position of the digits within them remains fixed.
Edge Difference
Digits outside the grid indicate the difference between the first and the last digit in the corresponding row or column.
Solving hints
R5C1 = R9C3; Take into account the differences in R5 and C3 :=> R5C1 = 9; R9C3 = 9; R5C9 = 2; R1C3 = 6;
Difference in R2 = pair {18}; no 1 or 8 in R8C456
No 9 in yellow shape; no 9 in purple shape and no 9 in R8C8. :=> 9 locked in R7C89 in green shape. :=> 9 also in R6C45. R4C8 = 9; R7C9 = 9; R6C4 = 9; R7C1 = 6; R9C5 = 6; R1C5 = 4 or 8; R7C4 = 4 or 8
6 not in green and purple shape; 6 in R8C9 + R6C2; R8C1 = 2; R9C6 = 2; 2 in R7C8 and R6C5 and R4C2
Edge sum in R4 = pair {37}; R4C456 = 1/4/6; R5C4 = R9C7. Must be 7. R1C7 = 2; R2C4 = 2
Difference in C8 :=> R9C8 = 1; R1C8 = 7; R5C3 = 1
Solution code: Column 4, followed by Column 6
Comments
on 9. December 2014, 08:24 by Statistica
Really, it looks like a photo of a tetris game...
on 6. December 2014, 15:17 by CHalb
@sf2l: No, take a look in the bottom left area.
