order independent hash?

[Dan Stromberg]

Two methods:
1) If you need your hash only once in an infrequent while, then save
the elements in a list, appending as needed, and sort prior to
hashing, as needed

2) If you need your hash more often, you could keep your elements in a
treap or red-black tree; these will maintain sortedness throughout the
life of the datastructure.

3) If A bunch of log(n) or n or nlog(n) operations doesn't sound
appealing, then you might try this one: Create some sort of mapping
from your elements to the integers.  Then just use a sum.  This won't
scatter things nearly as well as a cryptographic hash, but it's very
fast, because you don't need to reevaluate some of your members as you
go.

HTH

On 11/30/11, Neal Becker <ndbecker2 at gmail.com> wrote:
> I like to hash a list of words (actually, the command line args of my
> program)
> in such a way that different words will create different hash, but not
> sensitive
> to the order of the words.  Any ideas?
>
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