Being a mathematician by training, I chose to reduce this to two problems I have already solved (Permuting with duplicates and no memory and mapcar -- map for more than one list): 

use mapcar;

sub nCr {
    my( $r, @n )= @_;
    die "Usage: nCr($r,@n)"   if  @n < $r;
    my @pick= ( (0)x(@n-$r), (1)x$r );
    my @c;
    do {
        push @c, [mapcar{$_[0]?$_[1]:()}\@pick,\@n];
    } while(  nextpermute( @pick )  );
    return \@c;
}

for(  @{nCr(@ARGV)}  ) {
    print "[ ",join(", ",@$_)," ]\n";
}
__END__
> nCr 2 a b c
[ b, c ]
[ a, c ]
[ a, b ]

[download]
And, yes, it works for nC0 and nCn.

        - tye (but my friends call me "Tye")

In reply to (tye)Re: nCr arrays of size r by tye
in thread nCr arrays of size r by PsychoSpunk

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.