41 lines
864 B
Python
41 lines
864 B
Python
def kruskal(vs, es):
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f = []
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sets = [set(v) for v in vs]
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find_set = lambda v: [x for x in sets if v in x][0]
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def merge_sets_that_contains(u, v):
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setv = find_set(v)
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newsets = [x for x in sets if v not in x]
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newsets = [setv.union(x) if u in x else x for x in newsets]
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return newsets
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sorted_es = [e for e,w in sorted(es, key=lambda e: e[1])]
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for (u, v) in sorted_es:
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if find_set(u) != find_set(v):
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f += [(u, v)]
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sets = merge_sets_that_contains(u,v)
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return f
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if __name__ == '__main__':
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vs = [chr(i) for i in range(ord('a'), ord('h') + 1)]
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es = [
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(('a', 'b'), 1),
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(('b', 'c'), 5),
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(('c', 'd'), 3),
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(('d', 'a'), 7),
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(('e', 'f'), 2),
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(('f', 'g'), 6),
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(('g', 'h'), 8),
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(('h', 'e'), 4),
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(('b', 'f'), 10),
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(('c', 'e'), 9),
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(('d', 'h'), 11)
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]
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print(kruskal(vs,es))
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