This shading puzzle variation was created by Prasanna Seshadri and first appeared on the 2014 USPC.

PDF

or solve online (using our beta test of Penpa-Edit tools; use tab to shift between shading mode and the linex mode where left click+drag draws lines and right click marks X’s)

Theme: Clue Symmetry and Logic

Author/Opus: This is the 130th puzzle from our contributing puzzlemaster Prasanna Seshadri.

Rules: (Variation of Cave/Shading Puzzles). Shade some empty cells black to create a single connected group. Cells with numbers cannot be shaded, and the shaded cells cannot form a 2×2 square anywhere in the grid. Each numbered cell indicates the total count of shaded cells connected vertically and horizontally to that numbered cell.

Answer String: Enter the length in cells of each of the shaded segments from left to right for the marked rows, starting at the top. Separate each row’s entry from the next with a comma.

Time Standards (highlight to view): Grandmaster = 4:45, Master = 5:45, Expert = 11:30

Solution: PDF

Note: Follow this link for other Cave variations and this link for other classic Caves. If you are new to this puzzle type, here are our easiest Cave Puzzles to get started on.