This method changes the value of a cell in the puzzle. It also notifies the state change observer callback if there is one.
# - - - S u d o k u S o l v e r . _ _ s e t - - - def __set ( self, x, value ): """Set or clear one cell of the board. [ (x is an integer in [0,BOARD_L)) and (value is an integer in [0,MAT_L]) -> if self.changeObserver is not None -> notify self.changeObserver that cell x is being set to value in any case -> self.__board[x] := value ] """
The interface specification stipulates that the change
observer callback is called after
the state has changed, so our first task is to store the
new value in the board. We also track the number of
state changes in
#-- 1 -- self.__board[x] = value self.nStateChanges += 1
If there is a change observer callback, we have to
translate the internal index
to row and column values. See Section 5.19, “
Translate board position to row and column”.
#-- 2 -- # [ if self.changeObserver is not None -> # notify self.changeObserver that cell x is being # set to value if self.changeObserver is not None: row, col = self.__xToRowCol ( x ) self.changeObserver ( self, row, col, value )