Re: Creating tuples based on sets

Update: I missed the part about needing arbitrarily sized tuples. This only groups in sets of two...my bad. :(

Original message follows...

Ah, the joys of dot products. No need for recursion:

#!/usr/bin/perl -w

@set = qw(A B C);

print join("\n", map(join(',', @$_), @{&make_tuples(\@set, \@set)}));

sub make_tuples {
  my($set1, $set2) = @_;
  my @product;
  foreach my $x (0 .. $#$set1) {
    foreach my $y (0 .. $#$set2) {
      push(@product, [$set1->[$x], $set2->[$y]]);
    }
  }
  \@product;
}
[download]

I daresay I just answered a homework question for you, but so be it.

Matt

Comment on Re: Creating tuples based on sets Download Code

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Question by waxmop (Beadle) on Apr 16, 2003 at 15:31 UTC
At the end of the program, you just do `\@product;` [download] Does this do the same thing as `return \@product;` [download] ???	[reply] [d/l] [select]
Re: Re: Creating tuples based on sets by perlguy (Deacon) on Apr 16, 2003 at 15:31 UTC
There is a definite possibility that I am missing something, but isn't waxmop asking for something that will solve for an arbitrary number of elements (in the solution), not just 2 necessarily?	[reply]
Re: Re: Re: Creating tuples based on sets by waxmop (Beadle) on Apr 16, 2003 at 15:42 UTC
Yeah, I need the function to fit any of these situations: `my @set1 = qw(A B C D); my @set2 = qw(X Y Z); mk_tuples(@set1, 2); mk_tuples(@set2, 5);` [download] etc... Here's a side question. How come this doesnt' work in perl? `mk_tuples(["A", "B"], 3);` [download] I can't replace an array with just a list of elements.	[reply] [d/l] [select]
Re: Re: Re: Re: Creating tuples based on sets by perlguy (Deacon) on Apr 16, 2003 at 15:50 UTC
but you can... try this: `my $arrayref = ["A", "B"]; print join "\n", @$arrayref;` [download]	[reply] [d/l]


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