38 lines
1.1 KiB
Python
38 lines
1.1 KiB
Python
import heapq
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from collections import defaultdict
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def list_paths_dijkstra(graph, start, target):
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distances = defaultdict(lambda: float('inf'))
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paths = defaultdict(list)
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distances[start] = 0
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paths[start] = [[start]]
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pq = [(0, start)]
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while pq:
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curr_dist, node = heapq.heappop(pq)
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if curr_dist > distances[node]:
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continue
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for neighbor, weight in graph[node]:
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new_dist = curr_dist + weight
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if new_dist < distances[neighbor]:
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distances[neighbor] = new_dist
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paths[neighbor] = [path + [neighbor] for path in paths[node]]
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heapq.heappush(pq, (new_dist, neighbor))
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elif new_dist == distances[neighbor]:
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paths[neighbor].extend([path + [neighbor] for path in paths[node]])
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return paths[target]
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# Example usage:
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graph = {
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'A': [('B', 1), ('C', 1)],
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'B': [('D', 1)],
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'C': [('D', 1)],
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'D': []
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}
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start = 'A'
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target = 'D'
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print(list_paths_dijkstra(graph, start, target)) # Output: All shortest paths from 'A' to 'D'
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