>>11581564How can you not solve in polynomial time with the algorithm above?
Create a grid with nine (or the number of symbols for different sizes) bits per each square of sudoku.
For each known number, turn off the bits in its square, row and number.
Do the same for the newly appeared known numbers, until you know all thd numbers.
I don't see how this wouldn't solve it in polynomial time? Don't tell
me it's NP hard if it can be easily done by hand for the standard puzzle.
