def solve(gameBoard):
""" Run the sudoku solving algorithm on the given Board. """
if gameBoard.isFull(): return gameBoard
chosenSquare = mrv.ordering(gameBoard)
for someValue in lcv.ordering(gameBoard, chosenSquare):
# Place the provisional value on a test board.
testBoard = gameBoard.copy()
testBoard.placeValueAt(someValue, chosenSquare)
# Winnow domains by forward checking:
fwdcheck.checkBoard(testBoard, chosenSquare)
if not testBoard.areAllDomainsOpen(): continue
if runStats: bookkeeping.boardsPassedFwdcheck += 1
# Winnow domains further by AC3:
ac3.checkBoard(testBoard)
if not testBoard.areAllDomainsOpen(): continue
if runStats: bookkeeping.boardsPassedAc3 += 1
# Provisional value OK,
# punt down and try next square.
if doProg: bookkeeping.reportPunt()
puntBoard = solve(testBoard) # <--------- Recursive Call
if doProg: bookkeeping.reportShoonk()
if puntBoard is not None: return puntBoard
if runStats: bookkeeping.impossibleBoards += 1
return None # Implicitly no solution
def winnowDomainsByExistingValues(self):
"""
Used to establish existing domains
when a brand new (uncopied) board is created.
"""
for someSquare in [(row, col) for row in range(9) for col in range(9)
if (self.values[row][col] is not None)]:
fwdcheck.checkBoard(self, someSquare)