My guess is around a billion, but I do hope to come up with an accurate figure for the number ofSX-different gridsat some stage soon. As we did for SudokuP, we defineSX-equivalencein terms of the subset of Sudoku transformations that preserve the diagonal property. ...
the brute-force method can probably be done in a few tens of lines of code, but I don't care to wait upwards around 15 hours to for the computer to choose one of 5.5billion(thousand-millions) possibilities.
“solve” button looks like a single button, it’s actually 288 radio button labels stacked one on top of the other — but all of them look the same. Imagine a stack of cards: they all have the same design on the back, but different values on the front. The solver logic is ...
I didn't know until I tried them with a SAT solver, that N=4 (16x16) and N=5 (25x25), would work. I hit on the PM problem for 9x9, by luck, after following up on an hunch. The hunch was that there might be a vanilla sudoku grid with a large automorphism count, that was...