Cross the Caves by John Bulten

Cave by John Bulten


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: Sunken Lake

Author/Opus: This is the 54th puzzle from our contributing puzzlemaster John Bulten.

Rules: This puzzle is a combination of Cross the Streams and Cave rules (with the exception of having multiple “caves” that all connect to the edge of the grid).

Shade some empty cells black to create a single group of black cells that are all connected to each other through their edges. No 2×2 cell area within the grid contains all black cells. Numbers to the left/top of the grid represent the groups of consecutive black cells which are in that row/column in order, either from left to right or from top to bottom. A question mark (?) represents a group of consecutive black cells whose size is unknown; an asterisk (*) represents any number of unknown groups of black cells, including none at all.

All white cells must be connected via other white cells to an edge of the grid. All numbered cells inside the grid must be white and each number in these cells indicates the total count of white cells connected vertically and horizontally to the numbered cell including the cell itself.

See also this example:

Cave by Thomas Snyder

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

Time Standards (highlight to view): Grandmaster = 3:30, Master = 4:30, Expert = 9:00

Solution: PDF

Note: Follow this link for other Cross the Streams. Follow this link for other Cave variations and this link for other classic Caves. If you are new to Cave puzzles, here are our easiest Cave Puzzles to get started on. More Cave puzzles can be found in The Art of Puzzles and in Roger Barkan’s Colossal Cave Collection.

  • Joseph says:

    I solved this one, and a glance at the solutions file I received by email confirms that I got it right. But I’m having trouble entering the answer; it keeps saying “incorrect”.

    Maybe I’m misunderstanding the instructions for entering the answer. If you could give an answer string for the example puzzle (with a few selected rows), it may help.

    • Avatar photo drsudoku says:

      The answer string for the example, giving every row of the example, is “113,11,12,121,3,132,1,12”. This is every white segment in those rows (not the shaded segments).

  • Joseph says:

    Done! Thanks.

  • Michael says:

    Just curious: what software do you use to typeset these puzzles? Thanks!

    • Avatar photo drsudoku says:

      I’ve written my own code to generate postscript art directly from standard puzzle file definitions. The final polishing of PDFs, layout as ebooks, etc., is done in Illustrator and InDesign. If you are curious for some other approaches, this thread at Logic Masters India covers how some other authors have handled art for their sites.

  • JohnJBulten says:

    After solving, did you notice … ab pyhr bs rvgure glcr pna frr nal cneg bs gur vaare fvk-fdhner?

  • MountainManZach says:

    Penpa link: [EDIT: Removed as we added our own official link to post]

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