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lib/Algorithm/Loops.pm  view on Meta::CPAN

Each time you pass an array to a NextPermute* routine, the elements of
the array are shifted around to give you a new permutation.  If the
elements of the array are in reverse-sorted order, then the array is
reversed (in-place, making it sorted) and a false value is returned.
Otherwise a true value is returned.

So, if you start out with a sorted array, then you can use that as your
first permutation and then call NextPermute* to get the next permutation
to use, until NextPermute* returns a false value (at which point your
array has been returned to its original, sorted order).

So you would use NextPermute() like this:

    my @list= sort GetValuesSomehow();
    do {
        DoSomethingWithPermutation( @list );
    } while(  NextPermute( @list )  );

or, if your list only contains numbers, you could use NextPermuteNum()
like this: