Heyawake by Prasanna Seshadri
or solve online (using our beta test of Penpa-Edit tools; use tab to shift between shading mode and the composite Yajilin mode where left click marks cells, right click marks dots in cells or X’s on edges, left click+drag draws lines.)
Theme: Winner is You
Author/Opus: This is the 226th puzzle from our contributing puzzlemaster Prasanna Seshadri.
Rules: Shade some cells black so that all remaining white cells are connected as part of a single connected group; shaded cells cannot share an edge. No unbroken sequence of white cells in any row or column can cross two thick boundaries. A number in a region indicates the number of shaded cells in that region. Regions with no number may have any number of shaded cells. Cells with numbers can be shaded over.
Difficulty: 3.5 stars
Time Standards (highlight to view): Grandmaster = 3:45, Master = 7:30, Expert = 15:00
Solution: PDF; a solution video is also available here.
Note: Follow this link for other shading puzzles. More Heyawake puzzles are in Shading Variety Collection by Prasanna Seshadri.
I am confused by the instructions. Do we also need to add edges to turn the board into disjoint areas? Or are those floating edges there for cosmetic reason only?
Floating edges count as bold lines that cannot be crossed twice in a straight direction by consecutive white cells. If a floating edge does not form a closed wall with other parts of its region, then it does not create a separate region. This puzzle has 11 regions (9 4×4 boxes, with interior of R and O also being regions).
Great Heyawake puzzle! Now I’m a winner.