in reply to How to convert a script from C to Perl?

void swap(char *x, char *y)
{
    char temp;
    temp = *x;
    *x = *y;
    *y = temp;
}

void permute(char *a, int l, int r)
{
   int i;
   if (l == r)
     printf("%s\n", a);
   else
   {
       for (i = l; i <= r; i++)
       {
          swap((a+l), (a+i));
          permute(a, l+1, r);
          swap((a+l), (a+i)); //backtrack
       }
   }
}

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2018-03-11 Athanasius added code tags

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Re^2: How to convert a script from C to Perl?
by Anonymous Monk on Mar 11, 2018 at 17:22 UTC

    Here's one possible solution. No attempt was made to match the order in the generated sequence. 

    use Algorithm::Combinatorics qw( permutations );

my $iter = permutations( [split //, shift // q(how do you do)] );

while (my $p = $iter->next) {
    print join q(), @$p, "\n";
}

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    See Algorithm::Combinatorics for more info and examples.

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