Finnish Snakes

Here’s a pair of Finnish Snakes. One puzzle’s shaded givens (dark gray cells) are the others’ blank givens (light gray cells), and vice versa (ignoring the head and tail). Sticking to the symmetric layout and duality restrictions probably made both puzzles a little worse than what they could’ve been alone, though. I also couldn’t get the lengths match up.

I was going to use white/black circles instead of coloured cells, but couldn’t bother in the end.

Finnish Snake 1

Finnish Snake 2a


  • Shade some cells to form a snake.
  • The snake must use all dark gray cells, and none of the light gray cells.
  • The head and tail (numbered cells) are given, and indicate the snake’s length (49 and 47 cells long, respectively).
  • The snake doesn’t touch itself, even by corners.

EDIT: On the second snake, fixed the clue at R1C5.

  • Raphael says:

    Not getting the rules here – “One puzzle’s shaded givens are the other puzzle’s shaded givens?”

    • ArDeeJ says:

      Shade some cells to form a one-cell wide path traveling horizontally or vertically, starting from 1 and ending at 49 (47 in the other puzzle). The path must use the dark gray cells (shaded givens), and mustn’t use the light gray cells (blank givens).
      The path may not touch itself, even diagonally, meaning that the only shaded cells that can touch a shaded cell are the cells previous and next to it on the path.
      There must be a total of 49 (47 in the second puzzle) shaded cells, counting in the shaded givens as well.

      What you quoted wasn’t part of the rules, it describes how the two puzzles are related by theme. (Take any shaded given on one puzzle, the corresponding given will be blank, and vice versa, ignoring the head and tail.)

      I hope that clears things instead of confusing even more.

    • ArDeeJ says:

      Also, I meant to write “One puzzle’s shaded givens are the other puzzle’s blank givens”, but apparently I hadn’t. Fixed now, sorry.

  • Raphael says:

    Right-o. If you add, “One puzzle’s shaded givens (DARK GREY) are the other puzzle’s blank givens” it will be perfectly clear.
    (All caps are just so you can see it.)

  • […] Addendum 30-06-2014: Tapio Saarinen has a pair of colour-inverted Finnish Snake puzzles. […]

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