def depth_first(self, xy1, xy2):
"""Execute a depth first search."""
tile_col1, tile_row1 = self.the_map.xy_to_cr(xy1[0], xy1[1])
tile_col2, tile_row2 = self.the_map.xy_to_cr(xy2[0], xy2[1])
successor_to_parent_map = {}
start_state = (tile_col1, tile_row1)
successor_to_parent_map[(
start_state,
None)] = None # (Successor, Action) -> (Parent, Action)
open_list = Stack()
open_list.push((start_state, None))
closed = []
while not open_list.isEmpty():
current_state, action_to_current_state = open_list.pop()
if current_state == (tile_col2, tile_row2):
return self.__get_action_path(
(current_state, action_to_current_state),
successor_to_parent_map)
if current_state not in closed:
for successor_state, action, step_cost in self.__get_successors(
current_state):
open_list.push((successor_state, action))
if successor_state not in closed:
successor_to_parent_map[(successor_state, action)] = (
current_state, action_to_current_state)
closed.append(current_state)
return []
def depth_limited(problem, limit):
"""Depth Limited Search"""
frontier = Stack()
start_node = Node(problem['start'])
frontier.push(start_node)
closed_set = set()
while not frontier.isEmpty():
node = frontier.pop()
closed_set.add(node.value)
if goal_test(problem, node):
path = node.get_path()
cost = cal_path_cost(problem['graph'], path)
return path, cost, frontier.count
if node.depth == limit:
pass
else:
# Expansion
adj = problem['graph'].adj(node.value)
for child_value in quicksort(adj):
if push_or_not(problem, node, child_value, closed_set):
child_node = Node(child_value, node)
frontier.push(child_node)
return None
def convert(self, verbose):
self.verbose = verbose
operators = "^*+-\/"
# operands = string.ascii_lowercase + string.digits
output = Queue()
stack = Stack()
for token in self.infix:
operands = re.match("^[a-z]$|^\d+\.\d+$|^\d+$", token)
operators = re.match("^[+-\/*^]$", token)
# if token is a number or variable add it to putput
if operands:
output.push(token)
if self.verbose == True:
print "1 token = %s, output = %s" % (token, output.list[::-1])
# if the token is variable add it mapVariable dictionary
if token in string.ascii_lowercase:
self.mapVariables[token] = ""
# if token is an operator
elif operators:
# while there is another operator on the stack
while not stack.isEmpty():
# if operator is lef-associative and its precedence is less than or equal to that on stack, or operator has precedence less than that on stack (is not left-associative)
if stack.lastOnStack() != "(" and (
(
self.precedence[token][0] <= self.precedence[stack.lastOnStack()][0]
and self.precedence[token][1] == "L"
)
or self.precedence[token][0] < self.precedence[stack.lastOnStack()][0]
):
# push operator to output from stack
output.push(stack.pop())
if self.verbose == True:
print "2 token = %s, output = %s" % (token, output.list[::-1])
else:
break
# push operator to stack
stack.push(token)
if self.verbose == True:
print "3 token = %s, stack = %s" % (token, stack.list[::-1])
# if token is left parenthesis push it to stack
elif token == "(":
stack.push(token)
if self.verbose == True:
print "4 token = %s, stack = %s" % (token, stack.list[::-1])
# if token is right parenthesis
elif token == ")":
# until token at the top of stack is not left parethesis
while stack.lastOnStack() != "(":
# push from stack to output
output.push(stack.pop())
if self.verbose == True:
print "5 token = %s, output = %s" % (token, output.list[::-1])
# and pop left parethesis from stack but not to output
stack.pop()
if self.verbose == True:
print "Left on stack " + str(stack.list[::-1])
print "Output " + str(output.list)
self._rpn = output.list[::-1]
while len(stack.list) > 0:
self._rpn.append(stack.pop())
if self.verbose == True:
print "RPN value = " + str(self._rpn)
return self._rpn
def convert(self, verbose):
self.verbose = verbose
operators = '^*+-\/'
#operands = string.ascii_lowercase + string.digits
output = Queue()
stack = Stack()
for token in self.infix:
operands = re.match('^[a-z]$|^\d+\.\d+$|^\d+$', token)
operators = re.match('^[+-\/*^]$', token)
# if token is a number or variable add it to putput
if operands:
output.push(token)
if self.verbose == True:
print "1 token = %s, output = %s" % (token,
output.list[::-1])
# if the token is variable add it mapVariable dictionary
if token in string.ascii_lowercase:
self.mapVariables[token] = ''
#if token is an operator
elif operators:
# while there is another operator on the stack
while not stack.isEmpty():
# if operator is lef-associative and its precedence is less than or equal to that on stack, or operator has precedence less than that on stack (is not left-associative)
if stack.lastOnStack() != '(' and (
(self.precedence[token][0] <=
self.precedence[stack.lastOnStack()][0]
and self.precedence[token][1] == 'L')
or self.precedence[token][0] <
self.precedence[stack.lastOnStack()][0]):
# push operator to output from stack
output.push(stack.pop())
if self.verbose == True:
print "2 token = %s, output = %s" % (
token, output.list[::-1])
else:
break
# push operator to stack
stack.push(token)
if self.verbose == True:
print "3 token = %s, stack = %s" % (token,
stack.list[::-1])
# if token is left parenthesis push it to stack
elif token == '(':
stack.push(token)
if self.verbose == True:
print "4 token = %s, stack = %s" % (token,
stack.list[::-1])
# if token is right parenthesis
elif token == ')':
# until token at the top of stack is not left parethesis
while stack.lastOnStack() != '(':
# push from stack to output
output.push(stack.pop())
if self.verbose == True:
print "5 token = %s, output = %s" % (token,
output.list[::-1])
# and pop left parethesis from stack but not to output
stack.pop()
if self.verbose == True:
print "Left on stack " + str(stack.list[::-1])
print "Output " + str(output.list)
self._rpn = output.list[::-1]
while len(stack.list) > 0:
self._rpn.append(stack.pop())
if self.verbose == True:
print "RPN value = " + str(self._rpn)
return self._rpn