def forward_checking(state, verbose=False):
# Before running Forward checking we must ensure
# that constraints are okay for this state.
basic = basic_constraint_checker(state, verbose)
if not basic:
return False
# Add your forward checking logic here.
cur_var = state.get_current_variable()
if not cur_var:
return True
cur_val = None
cur_val = cur_var.get_assigned_value()
cons_list = state.get_constraints_by_name(cur_var.get_name())
for con in cons_list:
connect_var = state.get_variable_by_name(con.get_variable_j_name())
for val in connect_var.get_domain():
if not con.check(state, cur_val, val):
connect_var.reduce_domain(val)
if len(connect_var.get_domain()) == 0:
return False
return True
def forward_checking(state, verbose=False):
# Before running Forward checking we must ensure
# that constraints are okay for this state.
basic = basic_constraint_checker(state, verbose)
if not basic:
return False
var = state.get_current_variable()
if var!=None:
value = var.get_assigned_value()
constraints=state.get_constraints_by_name(var.get_name());
for c in constraints:
if state.get_variable_by_name(c.get_variable_i_name()) is var:
Y = state.get_variable_by_name(c.get_variable_j_name())
for val in Y.get_domain():
if c.check(state, value, val) is False:
Y.reduce_domain(val)
if Y.domain_size() is 0:
return False
elif state.get_variable_by_name(c.get_variable_j_name()) is var:
Y = state.get_variable_by_name(c.get_variable_i_name())
for val in Y.get_domain():
if c.check(state, val, value) is False:
Y.reduce_domain(val)
if Y.domain_size() is 0:
return False
return True
def forward_checking(state, verbose=False):
"""
Args:
state (CSPState)
"""
# Before running Forward checking we must ensure
# that constraints are okay for this state.
basic = basic_constraint_checker(state, verbose)
if not basic:
return False
# Add your forward checking logic here.
X = state.get_current_variable()
if not X:
return True
x = X.get_assigned_value()
# Loop through constraints
for c in state.get_constraints_by_name(X.get_name()):
var_i, var_j = c.get_variable_i_name(), c.get_variable_j_name()
Y_name = var_i if X.get_name() != var_i else var_j
Y = state.get_variable_by_name(Y_name)
for v in Y.get_domain():
if not c.check(state, x, v):
Y.reduce_domain(v)
if not Y.get_domain():
return False
# Return
return True
def forward_checking(state, verbose=False):
# Before running Forward checking we must ensure
# that constraints are okay for this state.
basic = basic_constraint_checker(state, verbose)
if not basic:
return False
X = state.get_current_variable()
if not X:
return True
x = X.get_assigned_value()
counter = 0
constraints = state.get_constraints_by_name(X.get_name())
while counter < len(constraints):
constraint = constraints[counter]
counter += 1
W = constraint.get_variable_j_name()
Z = constraint.get_variable_i_name()
if W == X.get_name():
Y = Z
else:
Y = W
Y = state.get_variable_by_name(Y)
for y in Y.get_domain():
if not constraint.check(state, x, y):
Y.reduce_domain(y)
if not Y.get_domain():
return False
return True
def forward_checking(state, verbose=False):
# Before running Forward checking we must ensure
# that constraints are okay for this state.
basic = basic_constraint_checker(state, verbose)
if not basic:
return False
var = state.get_current_variable()
value=None
if var is not None:
value = var.get_assigned_value()
constraints = state.get_constraints_by_name(var.get_name())
while constraints:
con = constraints.pop()
if con.get_variable_i_name() == var.get_name():
active=con.get_variable_j_name()
else:
active=con.get_variable_i_name()
j=state.get_variable_by_name(active)
for jval in j.get_domain():
a=con.check(state,value_i=value,value_j=jval)
if not a:
j.reduce_domain(jval)
if j.domain_size() == 0:
#print "\n------------\nTEST FAILS\n------------"
return False
return True
return True
def forward_checking(state, verbose=False):
# Before running Forward checking we must ensure
# that constraints are okay for this state.
basic = basic_constraint_checker(state, verbose)
if not basic:
return False
X = state.get_current_variable()
if not X:
return True
x = X.get_assigned_value()
counter = 0
constraints = state.get_constraints_by_name(X.get_name())
while counter < len(constraints):
constraint = constraints[counter]
counter += 1
W = constraint.get_variable_j_name()
Z = constraint.get_variable_i_name()
if W == X.get_name():
Y = Z
else:
Y = W
Y = state.get_variable_by_name(Y)
for y in Y.get_domain():
if not constraint.check(state, x, y):
Y.reduce_domain(y)
if not Y.get_domain():
return False
return True
def forward_checking(state, verbose=False):
# Before running Forward checking we must ensure
# that constraints are okay for this state.
basic = basic_constraint_checker(state, verbose)
if not basic:
return False
cur_var = state.get_current_variable()
if(cur_var == None):
return True # at root
ass_val = cur_var.get_assigned_value()
constraints = state.get_constraints_by_name(cur_var.get_name())
for const in constraints:
if(const.get_variable_i_name() == cur_var.get_name()):
other_var = state.get_variable_by_name(const.get_variable_j_name())
other_domain = other_var.get_domain()
for other_val in other_domain:
if( not const.check(state, value_i=ass_val, value_j=other_val)):
other_var.reduce_domain(other_val)
if(other_var.domain_size() == 0):
return False
return True
def forward_checking(state, verbose=False):
# Before running Forward checking we must ensure
# that constraints are okay for this state.
basic = basic_constraint_checker(state, verbose)
if not basic:
return False
# Add your forward checking logic here.
X = state.get_current_variable()
if X is None: return True
x = X.get_assigned_value()
for c in state.get_constraints_by_name(X.get_name()):
Y_name = c.get_variable_i_name()
i_is_y = True
if Y_name == X.get_name():
Y_name = c.get_variable_j_name()
i_is_y = False
Y = state.get_variable_by_name(Y_name)
for y in Y.get_domain():
if i_is_y:
passed = c.check(state, value_i=y, value_j=x)
else:
passed = c.check(state, value_i=x, value_j=y)
if not passed: Y.reduce_domain(y)
if len(Y.get_domain()) == 0: return False
return True
def forward_checking(state, verbose=False):
# Before running Forward checking we must ensure
# that constraints are okay for this state.
basic = basic_constraint_checker(state, verbose)
if not basic:
return False
variable = state.get_current_variable()
if not variable:
return True
variablename = variable.get_name()
constraints = state.get_constraints_by_name(variablename)
x = variable.get_assigned_value()
i = 0
for constraint in constraints:
connected_variable_name = constraint.get_variable_j_name()
connected_variable = state.get_variable_by_name(
connected_variable_name)
connected_domain = connected_variable.get_domain()
if connected_variable.is_assigned() == False:
for value in connected_domain:
if not constraint.check(state, x, value):
connected_variable.reduce_domain(value)
if not connected_variable.get_domain():
return False
return True
def forward_checking(state, verbose=False):
# Before running Forward checking we must ensure
# that constraints are okay for this state.
basic = basic_constraint_checker(state, verbose)
if not basic:
return False
# so far, all the assigned values satisfied the constraints
# in this state, some variable has been assigned, what we need to
# to do is check domain of the remaining unassigned variables
print "Before Check: state = ", state.vd_table()
new_state = state.copy()
current_var_name = new_state.get_current_variable_name()
constraints = new_state.get_constraints_by_name(current_var_name)
print "current variable :", current_var_name
for constraint in constraints:
print constraint
var_j_name = constraint.get_variable_j_name()
var_j = new_state.get_variable_by_name(var_j_name)
domain = var_j.get_domain()
for value in domain:
var_j.set_value(value)
if constraint.check(new_state):
continue
elif var_j.domain_size() > 1:
var_j.reduce_domain(value)
else:
return False
print "After Check: state = ", state.vd_table()
return True
def forward_checking(state, verbose=False):
# Before running Forward checking we must ensure
# that constraints are okay for this state.
basic = basic_constraint_checker(state, verbose)
if not basic:
return False
# Add your forward checking logic here.
# 1. Find X = x being the current assignment.
# 2. for each Y that is associated with X in a binary constraint; do
# for each y in Y's Domain; do
# if X=x and Y=y don't hold:
# remove y from Y's Domain
# if Y's Domain is empty:
# return False
# return True
# NOTE: This function is not a pure function. Its side-effect is
# to update the state
curr_var_name = state.get_current_variable_name()
if not curr_var_name:
# ROOT
return True
for constraint in state.get_constraints_by_name(curr_var_name):
var_j = state.get_variable_by_name(constraint.get_variable_j_name())
for val in var_j.get_domain():
if not constraint.check(state, value_i=None, value_j=val):
var_j.reduce_domain(val)
if var_j.domain_size() == 0:
return False
return True
def forward_checking(state, verbose=False):
# Before running Forward checking we must ensure
# that constraints are okay for this state.
basic = basic_constraint_checker(state, verbose)
if not basic:
return False
X = state.get_current_variable()
if X is None:
return True
x = X.get_assigned_value()
all_constraints = state.get_constraints_by_name(X.get_name())
for constraint in all_constraints:
if constraint.get_variable_i_name() == X.get_name():
Y = state.get_variable_by_name(constraint.get_variable_j_name())
else:
Y = state.get_variable_by_name(constraint.get_variable_i_name())
domain = Y.get_domain()
for y in domain:
if not constraint.check(state, x, y):
Y.reduce_domain(y)
if Y.domain_size() == 0:
return False
return True
def forward_checking(state, verbose=False):
# Before running Forward checking we must ensure
# that constraints are okay for this state.
basic = basic_constraint_checker(state, verbose)
if not basic:
return False
# Add your forward checking logic here.
raise NotImplementedError
def forward_checking(state, verbose=False):
# Before running Forward checking we must ensure
# that constraints are okay for this state.
basic = basic_constraint_checker(state, verbose)
if not basic:
return False
# Add your forward checking logic here.
raise NotImplementedError
def forward_checking(state, verbose=False):
# Before running Forward checking we must ensure
# that constraints are okay for this state.
basic = basic_constraint_checker(state, verbose)
if not basic:
return False
# Add your forward checking logic here.
X = state.get_current_variable()
if(not X is None):
#We proceed
x = X.get_assigned_value()
constraints = state.get_constraints_by_name(X.get_name())
else:
return True
def forward_checking(state, verbose=False):
# Before running Forward checking we must ensure
# that constraints are okay for this state.
basic = basic_constraint_checker(state, verbose)
if not basic:
return False
"""X = state.get_current_variable()
if X is not None:
x = X.get_assigned_value()
constraints = state.get_constraints_by_name(X.get_name())
for constraint in constraints:
if state.get_variable_by_name(constraint.get_variable_i_name()) == X:
Y_name = constraint.get_variable_j_name()
else:
Y_name = constraint.get_variable_i_name()"""
X = state.get_current_variable()
#THIS IS BEYOND FRUSTRATING
if X is not None:
x = X.get_assigned_value()
constraints = state.get_constraints_by_name(X.get_name())
for constraint in constraints:
if state.get_variable_by_name(constraint.get_variable_i_name()) == X:
Y_name = constraint.get_variable_j_name()
else:
Y_name = constraint.get_variable_i_name()
Y = state.get_variable_by_name(Y_name)
for y in Y.get_domain():
if constraint.check(state, x, y) is False:
Y.reduce_domain(y)
if Y.domain_size() is 0:
return False
return True
def forward_checking(state, verbose=False):
# Before running Forward checking we must ensure
# that constraints are okay for this state.
basic = basic_constraint_checker(state, verbose)
if not basic: return False
X = state.get_current_variable()
if X is None: return True
x = X.get_assigned_value()
X_name = X.get_name()
X_constraints = state.get_constraints_by_name(X_name)
for c in X_constraints:
Y_name = c.get_variable_j_name()
Y = state.get_variable_by_name(Y_name)
Y_domain = Y.get_domain()
for y in Y_domain:
if not c.check(state, value_i = x, value_j = y):
Y.reduce_domain(y)
if not Y.get_domain(): return False
return True
def forward_checking(state, verbose=False):
# Before running Forward checking we must ensure
# that constraints are okay for this state.
basic = basic_constraint_checker(state, verbose)
if not basic:
return False
variable = state.get_current_variable()
if(variable == None): return True
value = variable.get_assigned_value()
constraints = state.get_constraints_by_name(variable.get_name())
#for every constraint, get all possible values for the other constraint and check if they work
for constraint in constraints:
otherVariable = state.get_variable_by_name(constraint.get_variable_j_name())
domain = otherVariable.get_domain()
for otherVariableValue in domain:
if not constraint.check(state, value, otherVariableValue):
otherVariable.reduce_domain(otherVariableValue)
if otherVariable.domain_size() == 0:
return False
return True
def forward_checking(state, verbose=False):
# Before running Forward checking we must ensure
# that constraints are okay for this state.
basic = basic_constraint_checker(state, verbose)
if not basic:
return False
# Add your forward checking logic here.
X = state.get_current_variable()
if X != None:
x = X.get_assigned_value()
constraints = state.get_constraints_by_name(X.get_name())
for c in constraints:
Y = state.get_variable_by_name(c.get_variable_j_name())
for y in Y.get_domain():
if not c.check(state, x, y):
Y.reduce_domain(y)
if Y.domain_size() == 0:
return False
return True
def forward_checking(state, verbose=False):
# Before running Forward checking we must ensure
# that constraints are okay for this state.
basic = basic_constraint_checker(state, verbose)
if not basic:
return False
"""X = state.get_current_variable()
if X is not None:
x = X.get_assigned_value()
constraints = state.get_constraints_by_name(X.get_name())
for constraint in constraints:
if state.get_variable_by_name(constraint.get_variable_i_name()) == X:
Y_name = constraint.get_variable_j_name()
else:
Y_name = constraint.get_variable_i_name()"""
X = state.get_current_variable()
#THIS IS BEYOND FRUSTRATING
if X is not None:
x = X.get_assigned_value()
constraints = state.get_constraints_by_name(X.get_name())
for constraint in constraints:
if state.get_variable_by_name(
constraint.get_variable_i_name()) == X:
Y_name = constraint.get_variable_j_name()
else:
Y_name = constraint.get_variable_i_name()
Y = state.get_variable_by_name(Y_name)
for y in Y.get_domain():
if constraint.check(state, x, y) is False:
Y.reduce_domain(y)
if Y.domain_size() is 0:
return False
return True
def forward_checking(state, verbose=False):
# Before running Forward checking we must ensure
# that constraints are okay for this state.
basic = basic_constraint_checker(state, verbose)
if not basic:
return False
# Add your forward checking logic here.
#Upto this point the function only checks if the constraints are satisfied
#From here we have to reduce the domain of the variables that appear in the
#constraints
current_var = state.get_current_variable()
value = None
if current_var is not None:
var_val = current_var.get_assigned_value()
cons = state.get_constraints_by_name(current_var.get_name())
for constraint in cons:
var_i = state.get_variable_by_name(
constraint.get_variable_i_name())
var_j = state.get_variable_by_name(
constraint.get_variable_j_name())
if var_i.get_name() == current_var.get_name():
mVar = var_j
for value in mVar.get_domain():
if not constraint.check(state, var_val, value):
mVar.reduce_domain(value)
if len(mVar.get_domain()) == 0:
return False
else:
mVar = var_i
for value in mVar.get_domain():
if not constraint.check(state, value, var_val):
mVar.reduce_domain(value)
if len(mVar.get_domain()) == 0:
return False
return True
def forward_checking(state, verbose=False):
# Before running Forward checking we must ensure
# that constraints are okay for this state.
basic = basic_constraint_checker(state, verbose)
if not basic:
return False
var1 = state.get_current_variable()
if not var1:
return True
val1 = var1.get_assigned_value()
for c in state.get_constraints_by_name(var1.get_name()):
var2 = state.get_variable_by_name(c.get_variable_j_name())
for val2 in var2.get_domain():
if not c.check(state, val1, val2):
var2.reduce_domain(val2)
if not var2.get_domain():
return False
return True
def forward_checking(state, verbose=False):
# Before running Forward checking we must ensure
# that constraints are okay for this state.
basic = basic_constraint_checker(state, verbose)
if not basic:
return False
# forward checking logic
X = state.get_current_variable()
if not X: return True
x = X.get_assigned_value()
constraints = state.get_constraints_by_name(X.get_name())
for con in constraints:
Y = state.get_variable_by_name(con.get_variable_i_name(
) if con.get_variable_i_name() != X.get_name() else con.
get_variable_j_name())
for y in Y.get_domain():
if con.check(state, x, y) is False:
Y.reduce_domain(y)
if Y.domain_size() is 0:
return False
return True
def forward_checking(state, verbose=False, cur_var_data=None):
# Before running Forward checking we must ensure
# that constraints are okay for this state.
basic = basic_constraint_checker(state, verbose)
# Now that we've run basic_constraint_checker, we know that all assigned
# variables are valid. This means we only need to worry about domains
# in the next step; no need to concern ourselves with the validity of
# values.
if not basic:
return False
if 0 > state.variable_index:
return True
# MY_CODE
if cur_var_data is None:
# This default setting is used when this method alone is used for
# checking
cur_var = state.get_current_variable()
# Guaranteed to have an assigned value because it's the current
# variable in the state object.
cur_var_value = cur_var.get_assigned_value()
else:
# This alternate setting is used when this method is used as a
# helper to forward_checking_prop_singleton()
cur_var, cur_var_value = cur_var_data
neighbor_constraints = state.get_constraints_by_name(cur_var.get_name())
for constraint in neighbor_constraints:
neighbor = state.get_variable_by_name(constraint.get_variable_j_name())
# BEWARE: This domain is not a reference to the actual domain; it is
# a copy! One must call the reduce_domain() function to alter the
# domain
neighbor_domain = neighbor.get_domain()
for domain_possibility in neighbor_domain:
if not constraint.check(
state, value_i=cur_var_value, value_j=domain_possibility):
neighbor.reduce_domain(domain_possibility)
if not neighbor.get_domain():
return False
return True
def forward_checking(state, verbose=False):
# Before running Forward checking we must ensure
# that constraints are okay for this state.
basic = basic_constraint_checker(state, verbose)
if not basic:
return False
# Add your forward checking logic here.
# raise NotImplementedError
X= state.get_current_variable()
x= None
if X is not None:
x= X.get_assigned_value()
constants =state.get_constraints_by_name(state.get_current_variable_name())
for constant in constants:
Y= state.get_variable_by_name(constant.get_variable_j_name())
for y in Y.copy().get_domain():
if not constant.check(state, value_i=x, value_j=y):
Y.reduce_domain(y)
if Y.domain_size()==0:
return False
return True
def forward_checking(state, verbose=False):
# Before running Forward checking we must ensure
# that constraints are okay for this state.
basic = basic_constraint_checker(state, verbose)
if not basic:
return False
# Add your forward checking logic here.
var = state.get_current_variable()
value = None
if var is not None: # we are not in the root state
if var.is_assigned():
value = var.get_assigned_value()
#print 'var', var, 'is assigned to value', value
constraints = state.get_constraints_by_name(var.get_name())
for c in constraints:
#print 'Considering constraint', c
other_var_name = c.get_variable_i_name()
if other_var_name == var.get_name():
other_var_name = c.get_variable_j_name()
other_var = state.get_variable_by_name(other_var_name)
#print 'other var', other_var
for y in other_var.get_domain():
if not c.check(state, value, y):
#print 'constraint', c, 'failed for', value, y, 'remove it from domain'
other_var.reduce_domain(y)
if other_var.domain_size() == 0:
#print 'Domain is empty, return false'
return False
#print 'Evrything was ok, return True'
return True
else:
#print 'var', var, 'is not assigned to any value, return false'
return True
else:
#print 'We are at root state, return True'
return True
def forward_checking(state, verbose=False):
global cantLlamadas
cantLlamadas += 1
# Before running Forward checking we must ensure
# that constraints are okay for this state.
basic = basic_constraint_checker(state, verbose)
if not basic:
return False
# Add your forward checking logic here.
Xvar = state.get_current_variable()
if (Xvar == None):
return True
xval = Xvar.get_assigned_value()
constraints = state.get_constraints_by_name(Xvar.get_name())
for const in constraints:
if (const.get_variable_i_name() == Xvar.get_name()):
YvarName = const.get_variable_j_name()
Yvar = state.get_variable_by_name(YvarName)
for yval in Yvar.get_domain():
if (not const.check(state, value_i=xval, value_j=yval)):
Yvar.reduce_domain(yval)
elif (const.get_variable_j_name() == Xvar.get_name()):
YvarName = const.get_variable_i_name()
Yvar = state.get_variable_by_name(YvarName)
for yval in Yvar.get_domain():
if (not const.check(state, value_i=yval, value_j=xval)):
Yvar.reduce_domain(yval)
if (Yvar.domain_size() == 0):
return False
#Si no devolvi False todavia es que ninguna restriccion fallo
return True
def forward_checking(state, verbose=False):
# Before running Forward checking we must ensure
# that constraints are okay for this state.
basic = basic_constraint_checker(state, verbose)
if not basic:
return False
#X is the variable currently being assigned
X = state.get_current_variable()
value = None
if X is None:
return True #Thus this is the root of the search tree, since forward checking could only be done when there are variables to be assigned
x = X.get_assigned_value()
#All the binary constraints associated with X
constraints_list = state.get_constraints_by_name(X.get_name())
#For each constraint
for const in constraints_list:
#Y is the variable connected to X
#Choosing the connected Variable Y
if (const.get_variable_i_name != X.get_name()):
Y = state.get_variable_by_name(const.get_variable_i_name())
else:
Y = state.get_variable_by_name(const.get_variable_j_name())
for y in Y.get_domain():
#if not fulfilling constraint, remove y
if not const.check(state, x, y):
Y.reduce_domain(y)
if (Y.domain_size() == 0):
return False
return True
def forward_checking(state, verbose=False):
# Before running Forward checking we must ensure
# that constraints are okay for this state.
basic = basic_constraint_checker(state, verbose)
if not basic:
return False
# Add your forward checking logic here.
var = state.get_current_variable()
value = None
if not var: return True
value = var.get_assigned_value()
for constraint in state.get_constraints_by_name(var.get_name()):
#print(state)
my_constraint1=constraint.get_variable_i_name()
my_constraint2=constraint.get_variable_j_name()
my_constraint1_var=state.get_variable_by_name(my_constraint1)
my_constraint2_var=state.get_variable_by_name(my_constraint2)
my_constraint1_val=my_constraint1_var.get_assigned_value()
my_constraint2_val=my_constraint2_var.get_assigned_value()
if my_constraint1_var!=var:
my_constraint_var=my_constraint1_var
else:
my_constraint_var=my_constraint2_var
#my_constraint_var=state.get_variable_by_name(constraint.get_variable_i_name() if constraint.get_variable_i_name() != var.get_name() else constraint.get_variable_j_name())
for varvalue in my_constraint_var.get_domain():
if constraint.check(state,value,varvalue)==False:
#print(type(my_constraint_var.get_domain()))
my_constraint_var.reduce_domain(varvalue)
#print(my_constraint_var.get_domain())
if my_constraint_var.domain_size()==0:
return False
return True
def forward_checking(state, verbose=False):
# Before running Forward checking we must ensure
# that constraints are okay for this state.
basic = basic_constraint_checker(state, verbose)
if not basic:
return False
X = state.get_current_variable()
if not X:
return True
x = X.get_assigned_value()
#i = 0
constraints = state.get_constraints_by_name(X.get_name())
for i in xrange(len(constraints)):
constraint = constraints[i]
#i += 1
tempX = constraint.get_variable_i_name()
tempY = constraint.get_variable_j_name()
if tempX == X.get_name():
Y = tempY
else:
Y = tempX
Y = state.get_variable_by_name(Y)
for y in Y.get_domain():
if not constraint.check(state, x, y):
Y.reduce_domain(y)
if not Y.get_domain():
return False
return True
def forward_checking(state, verbose=False):
# Before running Forward checking we must ensure
# that constraints are okay for this state.
basic = basic_constraint_checker(state, verbose)
if not basic:
return False
# Add your forward checking logic here.
Xinstance = state.get_current_variable()
if Xinstance is not None:
Xvar = Xinstance.get_name()
xval = Xinstance.get_assigned_value()
all_binary_constraints = state.get_constraints_by_name(Xvar)
for binary_constraint in all_binary_constraints:
Yvar = binary_constraint.get_variable_j_name()
Yinstance = state.get_variable_by_name(Yvar)
for yval in Yinstance.get_domain():
if not binary_constraint.check(state, value_i=xval, value_j=yval):
Yinstance.reduce_domain(yval)
if Yinstance.domain_size() == 0:
return False
return True
def forward_checking(state, verbose=False):
# Before running Forward checking we must ensure
# that constraints are okay for this state.
# print "-"*10, "Inside forward_checking", "-"*10
basic = basic_constraint_checker(state, verbose)
if not basic:
return False
# return True if it's initial state
if state.variable_index < 0: return True
# print "Current Varialbe: {}, in State: \n{}".format(state.get_current_variable_name(), state.vd_table())
cur_var = state.get_current_variable()
# current variable is carried over when csp.solve() creates children
cur_var_name = state.get_current_variable_name()
cur_var_value = cur_var.get_assigned_value()
constraints = state.get_all_constraints()
# print "state current name: {}".format(state.get_current_variable_name())
# if cur_var_name == "5":
# for i in constraints:
# if cur_var_name == i.get_variable_i_name():
# if i.get_variable_j_name() == "4":
# print i#, "\t", i.get_variable_i_name(), i.get_variable_j_name()
# print i.check(state, "B", "O")
count_total = constraints.__len__()
count = 0
count_cont = 0
for constraint in constraints:
i_name = constraint.get_variable_i_name()
j_name = constraint.get_variable_j_name()
# !!! I assume as long as there is a constraint for two variables, they are connected to each other
if cur_var_name == i_name:
connected_name = j_name
elif cur_var_name == j_name:
connected_name = i_name
else:
count_cont += 1
continue
count += 1
# print "the {}/{} in constraint in constraints\n".format(count, count_total)
connected_var = state.get_variable_by_name(connected_name)
# print "connected_var: {}\n".format(connected_var)
# if not connected_var.is_assigned(): # comment this line, and unindent the next command and for loop
connected_domains = connected_var.get_domain()
# print "variable: {}, with domain: {}\n".format(connected_name, connected_var.get_domain())
for domain in connected_domains:
# in instruction, he says that constraints are symmetrical, so I assume I just need to check one direction
if not constraint.check(state, cur_var_value, domain):
# print "constraint.check in domain-in-connected_domains: {}".format("False")
# print "before reduce_domain: {}, __len__(): {}".format(connected_var, connected_var.domain_size())
connected_var.reduce_domain(domain)
# print "\nremove domain: {} from variable: {} at state: {} \n".format(domain, connected_var.get_name() ,state.variable_index)
# print "after reduce_domain: {}, __len__(): {}\n".format(connected_var, connected_var.domain_size())
#
# print "constraint.check in domain-in-connected_domains: {}".format("True")
if connected_var.domain_size() == 0:
# print "return False implemented\n"
# print "-" * 10, "End --- Inside forward_checking", "-" * 10, "\n"
return False
# print "return True implemented\n"
# print "-" * 10, "End --- Inside forward_checking", "-" * 10, "\n"
return True
# Add your forward checking logic here.
raise NotImplementedError