41 lines
1.1 KiB
Python
41 lines
1.1 KiB
Python
from Strategies.strat import PathFindingStrategy
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from Strategies.path import restore
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import heapq
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class AStar(PathFindingStrategy):
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def heuristic(self, a, b):
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return abs(a.x - b.x) + abs(a.y - b.y)
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def findPath(self, maze, start, exit):
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if exit is None:
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return [], 0
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heap = []
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counter = 0
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heapq.heappush(heap, (0, counter, start))
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counter += 1
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parent = {}
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g = {start: 0}
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visited = set()
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while heap:
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_, _, current = heapq.heappop(heap)
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if current == exit:
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break
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visited.add(current)
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for n in maze.getNeighbors(current):
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tentative = g[current] + 1
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if n not in g or tentative < g[n]:
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g[n] = tentative
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priority = tentative + self.heuristic(n, exit)
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heapq.heappush(heap, (priority, counter, n))
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counter += 1
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parent[n] = current
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return restore(parent, start, exit), len(visited) |