[Haskell-cafe] O(n) algorithm for determining subset

Eugene Kirpichov ekirpichov at gmail.com
Sun Nov 15 16:03:54 EST 2009


It's simpler: "x&~y == 0"

2009/11/15 Michael Mossey <mpm at alumni.caltech.edu>:
> Can someone tell me if this is correct. I'm guessing that if I represent
> two sets of integers by Word32 (where ith bit set means i is in the set),
> then an algorithm to determine if x is a subset of y would go something
> like
>
>
>  (y - x) == (y `exclusiveOr` x)
>
>
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-- 
Eugene Kirpichov
Web IR developer, market.yandex.ru


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