def test_dpll4(self):
clauses = [
'a || b', '!a || b || e', 'a || !b', 'b || !e', 'd || !e',
'!b || !c || !f', 'a || !e', '!b || f', '!b || c'
]
result = dpll(cnf.sentence('\n'.join(clauses)))
assert result == None
result = dpll(cnf.sentence('\n'.join(clauses[1:])))
assert result == {
'a': False,
'b': False,
'c': False,
'd': False,
'e': False,
'f': False
}
result = dpll(cnf.sentence('\n'.join(clauses[:-1])))
assert result == {
'a': True,
'b': True,
'c': False,
'd': False,
'e': False,
'f': True
}
def test_dpll_contrastive(self):
clauses = [
'a || b', '!a || b || e', 'a || !b', 'b || !e', 'd || !e',
'!b || !c || !f', 'a || !e', '!b || f', '!b || c', 'g1 || !a || b',
'g2 || !a || b', 'g3 || !a || b', 'g4 || !a || b', 'g5 || !a || b',
'g6 || !a || b', 'g7 || !a || b', 'g8 || !a || b', 'g9 || !a || b',
'g10 || !a || b', 'g11 || !a || b'
]
result = dpll(cnf.sentence('\n'.join(clauses)))
assert result == None
def solve(self):
def interpret_lit(l):
negate = (l[0] == "!")
if negate:
l = l[2:]
else:
l = l[1:]
d, i, j = l.split("_")
return d, i, j, negate
if len(self.contents()
) == 0: # short cut if nothing has been filled in
return SudokuBoard([[4, 1, 2, 3], [2, 3, 4, 1], [3, 4, 1, 2],
[1, 2, 3, 4]])
model = dpll(self.cnf())
if model is None:
return None
matrix = copy.deepcopy(self.matrix)
positive_literals = [l for l in model if model[l] == 1]
for l in positive_literals:
d, i, j, _ = interpret_lit(l)
matrix[int(i) - 1][int(j) - 1] = int(d)
return SudokuBoard(matrix)
def test_dpll3(self):
clauses = ['a || b', '!a || b', 'a || !b', '!a || !b']
result = dpll(cnf.sentence('\n'.join(clauses)))
assert result == None
def test_dpll2(self):
clauses = ['a || b', '!a || !b']
result = dpll(cnf.sentence('\n'.join(clauses)))
assert result == {'a': False, 'b': True}