Windows

RulesEdit

   

Blacken exactly two cells in each outlined 2x2 window to form one connected set of black cells which doesn't touch itself, not even diagonally. There cannot be a 2x2 square of four cells with the same colour (black or white) anywhere in the grid.

(Rules and example from WPC 2009 IB)

History of the puzzleEdit

WPC 2009 IB lists Mehmet Murat Sevim (Turkey) as an originator of the idea.

VariantsEdit

Windows WindowsEdit

   

First appeared on WPC 2017/Round 4. Author of the puzzle was Prasanna Seshadri (India). This name is in a reference to previous Windows variants such as Windows Nurikabe, also by Prasanna.

Blacken exactly two cells in each outlined 2x2 window to form one connected set of black cells which doesn't touch itself, not even diagonally. There cannot be a 2x2 square of four cells with the same colour (black or white) anywhere in the grid.

Also, there are some dotted areas. Two such dotted areas forming the same shape without rotation/reflection form a ‘pair’. For cells in the same position in a pair, exactly one of the cells must be shaded and the other must be left white.

(Rules (modified) and example from WPC 2017 IB)

Appearances in the past WPCsEdit