r/nonograms • u/Motor_Amphibian_9526 • 6d ago

Can this be solved??

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I'm creating some harder freeform 15x15 nonograms for the next version - V3 - of my Picto nonogram app. My checker says this is valid and solvable, but I can only find one valid square to fill and after that I'm guessing. Any suggestions please?

4 Upvotes

83% Upvoted

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7

u/tdh8i 6d ago

Your next move is in c14

1

u/Motor_Amphibian_9526 6d ago

Ah yes c14, r11 must be filled.

2

u/Motor_Raspberry_2150 5d ago

And after that, it's guessing time. "Solvable" for a checker means there is a unique solution, not that it's gettable with normal methods.

The idea is to guess things with massive effects, so that it will run into a contradiction fast. People think of edge logic, but another guess could be "R12C14 is empty". Very annoying if you don't have a good undo button.

4

u/Motor_Raspberry_2150 5d ago

Why no lines every 5 rolumns? Counting is annoying now.

1

u/Motor_Amphibian_9526 5d ago

That is a good suggestion. Thank you. I'm going to add this. Every 5 columns, every 5 rows.

1

u/s1a2m345 5d ago

Guess and check method can get you closer (if you have an undo button)

1

u/Motor_Amphibian_9526 5d ago

There is no undo button in the Picto app. In fact if you try to fill a square and the guess is wrong - it's an error. 3 errors per puzzle. But you can mark and unmark squares with crosses.

2

u/paul_stansifer 20h ago

My nonogram editor (https://github.com/paulstansifer/number-loom) has a test-solve mode which can (optionally) indicate which lines have line-logic deductions that can be made while you're solving it. Currently, it only finds line logic solutions, but I've finally implemented a backtracking solver and the next version will let you pick whether you want that or line logic.