Double Dutch Sudoku Advent (15) - Even Sandwich vs. Point to Next
(Published on 15. December 2014, 12:00 by Richard)
Eisbär (Arvid) 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.
Even Sandwich
Place the digits from 1 to 9 in every row, column and 3x3-block. Clues outside the grid show all the digits that have even digits as neighbours on both sides in the corresponding row or column.
Point to Next
If a digit N is placed in a cell containing an arrow, then the digit N+1 must be placed in a cell pointed at by the arrow.
Solving hints
Even Sandwich vs Point to Next
The most important hint fort his puzzle is to look for places that must be odd/even or may not be odd/even.
Look for example to R8. 9 is sandwiched there, so R8C3 and R8C5 are even. Since 9 is the only sandwiched digit, R8C1 and R8C7 must be odd to avoid another sandwiched digit.
Solution code: Row 5, followed by column 5
Comments
on 2. April 2022, 22:53 by Nick Smirnov
Penpa:
https://tinyurl.com/y8usj5qq
