139 lines
4.2 KiB
Python
139 lines
4.2 KiB
Python
import math
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import queue
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from dataclasses import dataclass, field
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from typing import Any
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from domain.world import World
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class State:
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def __init__(self, x, y, direction=(1, 0)):
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self.x = x
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self.y = y
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self.direction = direction
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def __hash__(self):
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return hash((self.x, self.y))
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def __eq__(self, other):
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return (self.x == other.x and self.y == other.y
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and self.direction == other.direction)
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class Node:
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def __init__(self, state: State):
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self.state = state
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self.parent = None
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self.action = None
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self.g = 0
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self.h = 0
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@dataclass(order=True)
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class PrioritizedItem:
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priority: int
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item: Any = field(compare=False)
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def __iter__(self):
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return iter((self.priority, self.item))
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def action_sequence(node: Node):
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actions = []
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while node.parent:
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actions.append(node.action)
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node = node.parent
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print(node.g)
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actions.reverse()
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return actions
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class RotateAndGoAStar:
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def __init__(self, world: World, start_state: State, goal_state: State):
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self.world = world
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self.start_state = start_state
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self.goal_state = goal_state
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self.fringe = queue.PriorityQueue()
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self.enqueued_states = {}
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self.explored = set()
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self.actions = []
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def search(self):
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h = abs(self.start_state.x - self.goal_state.x) ** 2 + abs(self.start_state.y - self.goal_state.y) ** 2
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self.fringe.put(PrioritizedItem(h, Node(self.start_state)))
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while not self.fringe.empty():
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priority, elem = self.fringe.get()
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self.enqueued_states.pop(elem, 0)
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if self.is_goal(elem.state):
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self.actions = action_sequence(elem)
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return True
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self.explored.add(elem.state)
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for (action, state) in self.successors(elem.state):
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next_node = Node(state)
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next_node.action = action
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next_node.parent = elem
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next_node.g = (elem.g
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+ abs(elem.state.x - state.x)
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+ abs(elem.state.y - state.y)
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+ self.world.get_cost(state.x, state.y)
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)
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next_node.h = abs(state.x - self.goal_state.x) + abs(state.y - self.goal_state.y)
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self.print_fringe()
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f = next_node.g + next_node.h
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if state not in self.enqueued_states and state not in self.explored:
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self.fringe.put(PrioritizedItem(f, next_node))
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self.enqueued_states[state] = f
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elif self.enqueued_states.get(state, -math.inf) > f:
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self.add_existed(next_node, f)
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self.enqueued_states.pop(state, 0)
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self.enqueued_states[state] = f
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return False
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def print_fringe(self):
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elems = []
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while not self.fringe.empty():
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e = self.fringe.get()
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elems.append(e)
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print(str(e.item.state.x) + ":" + str(e.item.state.x))
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for e in elems:
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self.fringe.put(e)
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def add_existed(self, node: Node, f: int):
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old = []
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while not self.fringe.empty():
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e = self.fringe.get()
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if e.item.state == node.state:
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break
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old.append(e)
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self.fringe.put(PrioritizedItem(f, node))
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for e in old:
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self.fringe.put(e)
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def successors(self, state: State):
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new_successors = [
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# rotate right
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("RR", State(state.x, state.y, (-state.direction[1], state.direction[0]))),
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# rotate left
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("RL", State(state.x, state.y, (state.direction[1], -state.direction[0]))),
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]
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if self.world.accepted_move(state.x + state.direction[0], state.y + state.direction[1]):
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new_successors.append(
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("GO", State(state.x + state.direction[0], state.y + state.direction[1], state.direction)))
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return new_successors
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def is_goal(self, state: State) -> bool:
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return (
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state.x == self.goal_state.x
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and state.y == self.goal_state.y
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)
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