Perfect numbers: Difference between revisions
Content added Content deleted
m (→{{header|Python}}: Updated a primitive ( concatMap )) |
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Or, a little faster (by restricting the search space): |
Or, a little faster (by restricting the search space): |
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<lang python>from |
<lang python>from itertools import (chain) |
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from math import (sqrt) |
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lows + concatMap( |
lows + concatMap( |
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lambda x: ( |
lambda x: ( |
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lambda y=n / x: [y] |
lambda y=(n / x): [y] if x != y else [] |
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if x != y |
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else [] |
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)() |
)() |
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)(lows) |
)(lows) |
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# concatMap :: (a -> [b]) -> [a] -> [b] |
# concatMap :: (a -> [b]) -> [a] -> [b] |
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def concatMap(f): |
def concatMap(f): |
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return lambda xs: list( |
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chain.from_iterable( |
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map(f, xs) |
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) |
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) |
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return lambda xs: go(xs) |
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if __name__ == '__main__': |
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main()</lang> |
main()</lang> |
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{{Out}} |
{{Out}} |
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<pre>[6, 28, 496, 8128]</pre> |
<pre>[6, 28, 496, 8128]</pre> |
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