SecUSo / privacy-friendly-sudoku

Privacy Friendly App to play Sudoku on Android.
https://secuso.org/pfa-sudoku
GNU General Public License v3.0
151 stars 57 forks source link

[Feature Request] Automatically compute pencil marks #119

Open andbenn opened 5 months ago

andbenn commented 5 months ago

As a user, I'd like to save half of my game duration play time, and have the pencil marks for the current board computed and displayed.

There may be cases where I started and have a error I don't see, and pencil marks can't be computed. An error or requirement that pencil marks can only be computed at start or first is ok.

arifz commented 3 months ago

Some suggestions for a partial implementation of the auto-fill pencil marks

My way of pencil marks is to select a digit and then pencil in all the possible places where it could possibly be. Sometimes the digit is entirely missing, in which case I have to enter that digit in all the open squares. At other times, there are only one or two of that digit present on the initial board. Even in that case, it would be helpful to have a button which could fill all the square with the chosen digit, after which I could remove the few places which are not possible, by simply removing one row one column and one box.

For the extreme case, if you simply count how many moves it takes, I am sure that if I started from a board where all the digits were penciled in, in all the empty squares, it would take less time to remove the unwanted marks, than it does to start from a blank board where we pencil in all the marks.