17 lines
417 B
Python
17 lines
417 B
Python
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class S_of_n_creator():
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def __init__(self, n):
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self.n = n
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self.i = 0
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self.sample = []
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def __call__(self, item):
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self.i += 1
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n, i, sample = self.n, self.i, self.sample
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if i <= n:
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# Keep first n items
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sample.append(item)
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elif randrange(i) < n:
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# Keep item
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sample[randrange(n)] = item
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return sample
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