def create_sudoku_csp(filename):
"""Instantiate a CSP representing the Sudoku board found in the text
file named 'filename' in the current directory.
"""
csp = CSP()
board = list(map(lambda x: x.strip(), open(filename, 'r')))
for row in range(9):
for col in range(9):
if board[row][col] == '0':
csp.add_variable('%d-%d' % (row, col), map(str, range(1, 10)))
else:
csp.add_variable('%d-%d' % (row, col), [board[row][col]])
for row in range(9):
csp.add_all_different_constraint(
['%d-%d' % (row, col) for col in range(9)])
for col in range(9):
csp.add_all_different_constraint(
['%d-%d' % (row, col) for row in range(9)])
for box_row in range(3):
for box_col in range(3):
cells = []
for row in range(box_row * 3, (box_row + 1) * 3):
for col in range(box_col * 3, (box_col + 1) * 3):
cells.append('%d-%d' % (row, col))
csp.add_all_different_constraint(cells)
return csp
def initialize_sudoku():
csp = CSP()
N = 4
BLOCK = 2
rule = "x != y"
for i in range(N):
for j in range(N):
csp.add_variable("(%s, %s)" % (i, j), list(range(N)))
for x1 in range(N):
for y1 in range(N):
for x2 in range(N):
for y2 in range(N):
neighbors = False
if x1 == x2: neighbors = True
if y1 == y2: neighbors = True
if x1 // BLOCK == x2 // BLOCK and y1 // BLOCK == y2 // BLOCK:
neighbors = True
if neighbors:
csp.add_constraint("(%s, %s)" % (x1, y1),
"(%s, %s)" % (x2, y2), rule)
csp.export_to_json("sudoku.json")
csp.all_solutions = False
solution = csp.solve()
board = [[0] * N for i in range(N)]
print(len(board))
for key, value in solution.items():
print(key[1], key[4], value)
board[int(key[1])][int(key[4])] = value[0]
for i in range(N):
print(board[i])
def create_map_coloring_csp():
"""Instantiate a CSP representing the map coloring problem from the
textbook. This can be useful for testing your CSP solver as you
develop your code.
"""
csp = CSP()
states = ['WA', 'NT', 'Q', 'NSW', 'V', 'SA', 'T']
edges = {'SA': ['WA', 'NT', 'Q', 'NSW', 'V'],
'NT': ['WA', 'Q'], 'NSW': ['Q', 'V']}
colors = ['red', 'green', 'blue']
for state in states:
csp.add_variable(state, colors)
for state, other_states in edges.items():
for other_state in other_states:
csp.add_constraint_one_way(state, other_state, lambda i, j: i != j)
csp.add_constraint_one_way(other_state, state, lambda i, j: i != j)
return csp
def initialzing_NQueen(N):
csp = CSP()
rule = "x[0] != y[0] and x[1] != y[1] and abs((x[0] - y[0]) / (x[1] - y[1])) != 1"
for v in range(N):
csp.add_variable(str(v), [[x, y] for x in range(N) for y in range(N)])
for x in csp.variables:
for y in csp.variables:
if x != y:
csp.add_constraint(x, y, rule)
csp.solve()
csp.save_solution()
# print(csp.solutions)
return csp
