019f8fd211
git-subtree-dir: users/wpcarro git-subtree-mainline:464bbcb15cgit-subtree-split:24f5a642afChange-Id: I6105b3762b79126b3488359c95978cadb3efa789
40 lines
1.2 KiB
Python
40 lines
1.2 KiB
Python
from heapq import heappush, heappop
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import random
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def shortest_path(a, b, graph):
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seen = set()
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h = []
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heappush(h, (0, a, [a]))
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while h:
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km, x, path = heappop(h)
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if x == b:
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return path
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for c in graph[x]:
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if c not in seen:
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heappush(h, (km + 1, c, path + [c]))
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raise Exception("We were unable to find a path from {} to {}".format(a, b))
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graph = {
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'Min' : ['William', 'Jayden', 'Omar'],
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'William' : ['Min', 'Noam'],
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'Jayden' : ['Min', 'Amelia', 'Ren', 'Noam'],
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'Ren' : ['Jayden', 'Omar'],
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'Amelia' : ['Jayden', 'Adam', 'Miguel'],
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'Adam' : ['Amelia', 'Miguel', 'Sofia', 'Lucas'],
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'Miguel' : ['Amelia', 'Adam', 'Liam', 'Nathan'],
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'Noam' : ['Nathan', 'Jayden', 'William'],
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'Omar' : ['Ren', 'Min', 'Scott'],
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'Liam' : ['Ren'],
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'Nathan' : ['Noam'],
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'Scott' : [],
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}
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result = shortest_path('Jayden', 'Adam', graph)
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print(result)
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assert result == ['Jayden', 'Amelia', 'Adam']
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print('Success!')
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beg = random.choice(list(graph.keys()))
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end = random.choice(list(graph.keys()))
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print("Attempting to find the shortest path between {} and {}".format(beg, end))
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print(shortest_path(beg, end, graph))
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