Files
exercise-00/pig_lite/problem/base.py
2025-10-07 18:22:35 +02:00

93 lines
2.7 KiB
Python

import hashlib
class Node(object):
def __init__(self, parent, state, action, cost, depth):
self.parent = parent
self.state = state
self.action = action
self.cost = cost
self.depth = depth
def key(self):
# if state is composed of other stuff (dict, set, ...)
# make it a tuple containing hashable datatypes
# (this is supposed to be overridden by subclasses)
return self.state
def __hash__(self):
return hash(self.key())
def __eq__(self, other):
if type(self) == type(other):
return self.key() == other.key()
raise ValueError('cannot simply compare two different node types')
def __str__(self):
return self.__repr__()
def __repr__(self):
return 'Node(id:{}, parent:{}, state:{}, action:{}, cost:{}, depth:{})'.format(
id(self),
id(self.parent),
self.state,
self.action,
self.cost,
self.depth
)
def get_action_sequence(self):
current = self
reverse_sequence = []
while current.parent is not None:
reverse_sequence.append(current.action)
current = current.parent
return list(reversed(reverse_sequence))
def get_action_sequence_hash(self):
action_sequence = self.get_action_sequence()
action_sequence_as_str = ','.join(map(str, action_sequence))
action_sequence_hash = hashlib.sha256(action_sequence_as_str.encode('UTF-8')).hexdigest() # should solution node return hashcode?
return action_sequence_hash
def pretty_print(self):
print(f"state {self.state} was reached following the sequence {self.get_action_sequence()} (cost: {self.cost}, depth: {self.depth})")
class Problem(object):
def get_number_of_expanded_nodes(self):
raise NotImplementedError()
def get_start_node(self):
raise NotImplementedError()
def get_end_node(self):
raise NotImplementedError()
def is_end(self, node):
raise NotImplementedError()
def action_cost(self, state, action):
raise NotImplementedError()
def successors(self, node):
raise NotImplementedError()
def to_json(self):
raise NotImplementedError()
def visualize(self, **kwargs):
raise NotImplementedError()
def get_action_sequence(self, end: Node):
if end is None:
return list()
return end.get_action_sequence()
@staticmethod
def from_json(jsonstring):
raise NotImplementedError()
@staticmethod
def get_minimum_problem_size():
raise NotImplementedError()