def solve(puz: puzzle) -> None:
"""
Main code for solving a single puzzle.
:param puz:
:return:
"""
poss1 = []
poss2 = generatePossible(puz)
# Makes sure all single and hidden solved
while not puz.solved() and poss2 != poss1:
poss1 = poss2
solveSingles(puz)
solveHidden(puz)
poss2 = generatePossible(puz)
# If it is not solved move into brute forcing the solution
if puz.validPuzzle():
if not puz.solved():
print('Some brute force required.')
try:
# Opens thread to run brute force on
thread = threading.Thread(target=bruteForce,
args=[puz],
daemon=True)
thread.start()
count = 0
# Counts how much time has passed to make sure not to long has gone, and that the thread is still alive
while not puz.solved() and count < 300 and thread.is_alive():
time.sleep(.5)
count += 1
except:
print('Threading error.')
if not puz.solved():
print('Puzzle was unable to be solved.')
else:
print('Invalid puzzle')
def eliminateSingles(puz: puzzle) -> None:
"""
This function iterates through a puzzle and if only one value is possible for a cell it fills it with that value.
:param puz: puzzle
:return:
"""
poss = generatePossible(puz)
for row in range(9):
for col in range(9):
if len(poss[row][col]) == 1:
puz.setValue(row, col, poss[row][col][0])
poss = generatePossible(puz)
def findNextEmpty(puz: puzzle, i: int, j: int) -> tuple:
"""
This function goes through a puzzle and returns a tuple of the coordinates of the next empty cell, if none found
then -1,-1 is returned.
:param puz: puzzle
:param i: int
:param j: int
:return: tuple
"""
for row in range(i, 9):
for col in range(j, 9):
if not puz.getValue(row, col):
return row, col
for row in range(9):
for col in range(9):
if not puz.getValue(row, col):
return row, col
return -1, -1
def bruteForce(puz: puzzle, row: int = 0, col: int = 0) -> bool:
"""
Systematically goes through the puzzle and back tracks on dead end until puzzle is solved.
:param puz: puzzle
:param col: int
:param row: int
:return: bool
"""
poss = generatePossible(puz)
row, col = findNextEmpty(puz, row, col)
if row == -1:
return True
for val in poss[row][col]:
if puz.setValue(row, col, val):
if bruteForce(puz, row, col):
return True
puz.clearValue(row, col)
return False
def solveSingles(puz: puzzle) -> None:
"""
This function goes through and solves all the singles of a puzzle until none are left.
:param puz: puzzle
:return:
"""
poss1 = []
poss2 = generatePossible(puz)
while not puz.solved() and poss2 != poss1:
poss1 = poss2
eliminateSingles(puz)
poss2 = generatePossible(puz)
def solveHidden(puz: puzzle) -> None:
"""
Loops through the puzzle until all the hidden have been solved.
:param puz: puzzle
:return:
"""
poss1 = []
poss2 = generatePossible(puz)
while not puz.solved() and poss2 != poss1:
poss1 = poss2
eliminateHidden(puz)
poss2 = generatePossible(puz)
def generatePossible(puz: puzzle) -> list:
"""
This function takes in a puzzle and returns a 2D list of all the valid moves for a space.
:param puz: puzzle
:return: list
"""
poss = []
for row in range(9):
poss.append([])
for col in range(9):
poss[row].append([])
for val in range(1, 10):
if not puz.checkSpot(row, col, val):
poss[row][col].append(val)
return poss
def eliminateHidden(puz: puzzle) -> None:
"""
This function takes in a puzzle and solves all the hidden singles one time.
:param puz: puzzle
:return:
"""
# Checking for hidden singles in rows
for row in range(9):
for val in range(1, 10):
count = 0
poss = generatePossible(puz)
for col in range(9):
if val in poss[row][col]:
count += 1
rowPoss = row
colPoss = col
if count == 1:
puz.setValue(rowPoss, colPoss, val)
# Checking for hidden singles in columns
for col in range(9):
for val in range(1, 10):
count = 0
poss = generatePossible(puz)
for row in range(9):
if val in poss[row][col]:
count += 1
rowPoss = row
colPoss = col
if count == 1:
puz.setValue(rowPoss, colPoss, val)
# Checking for hidden singles in blocks
for block in range(9):
for val in range(1, 10):
count = 0
poss = generatePossible(puz)
for row in range(3):
for col in range(3):
if val in poss[row + block // 3 * 3][col + block % 3 * 3]:
count += 1
rowPoss = row
colPoss = col
if count == 1:
puz.setValue(rowPoss, colPoss, val)