12 lines
259 B
Python
12 lines
259 B
Python
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>>> def happy(n):
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past = set()
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while n != 1:
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n = sum(int(i)**2 for i in str(n))
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if n in past:
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return False
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past.add(n)
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return True
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>>> [x for x in xrange(500) if happy(x)][:8]
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[1, 7, 10, 13, 19, 23, 28, 31]
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