As I mentioned during this week’s developer journal, I have a minor announcement to make.

A solved nonogram

It might be a bit shaky until I get the nightly script right, and there’s nothing like a scoreboard or mitigation against cheating, but for people who want to try out the Picture to Nonogram generated puzzles, I now post a daily puzzle at https://john.colagioia.net/nono/.

The styling is a variation of the main site/blog, which was always my intention with the color scheme, but never found a place to do that.

Prior puzzles are archived in subfolders named after the date in YYYYMMDD format, so you can find Friday’s at https://john.colagioia.net/nono/20210219/, for example, and I’ll eventually put up a generated archive page for easier access.

How to Play

If you’re not familiar with solving these puzzles, the numbers in the margins are the consecutive runs of dark squares. Assuming that the picture has the right light/dark balance, it should be straightforward to compare the vertical and horizontal runs to find many of the intersection points, which should suggest where some in-between pixels go, hopefully providing further information.

Cells that are light can both be marked as light or unmarked to be correct.

For more information, Wikipedia’s article on the puzzle has some more detail.

Cheating

If you need an occasional huge hint, you can run the following code in the developer console.

grid
  .map((row) => row
    .map((cell) => [
      1 - cell[0],
      cell.length > 1 ? cell.slice(-1)[0] : -1
    ])
  )
  .map((row) => row
    .map((cell) => cell[0] === cell[1] || (cell[0] === 0 && cell[1] < 0))
  )
  .map((row) => row.filter((cell) => !cell))
  .filter((row) => row.length > 0);

This will return an item for each unsolved row, where each item counts the number of cells that aren’t right. It doesn’t point to a solution, but it should be enough information to guide you to the solution, especially in cases where the puzzle is legitimately ambiguous.

Credits: No actual credits; the header image is just a screenshot of a solved puzzle.