One or All
Rules[edit]
Place a digit from 1 to 3 into each cell so that each thickly outlined region contains either the same digit in all cells or a different digit in each cell. If two cells are separated by a thick outline, they must contain different digits.
(Rules and example from WPC 2017 IB)
History of the puzzle[edit]
Invented by Naoki Inaba (Japan) in 2002 under the name ワンorオール (transliteration of "One or All"). First set of puzzles he created can be seen on his website. [1]
Appearances in the past WPCs[edit]
- WPC 2017/Round 16 by Deb Mohanty