Your algorithm does not accurately represent how one would achieve grouping of decks in real life. The easiest way to do that would almost certainly be to sort. First by suit, creating 4 individual piles. And the sorting each suit pile by rank. And finally separating the larger sorted pile of cards into individual decks.

The following script represents this algorithmically: 
use List::Util qw(shuffle);

use strict;

# Ordered least to greatest
my @suit = qw(C D H S);
my @rank = ( 2 .. 10, qw(J Q K A) );

# Construct a standard deck
my @card = map {
    my $suit = $_;
    map { "$_$suit" } @rank
} @suit;

# Shuffle 4 piles of cards.
my @pile = shuffle( (@card) x 4 );

print "Pile\n\t@pile\n\n";

# Sort
my %ord_suit = map { $suit[$_] => $_ } ( 0 .. $#suit );
my %ord_rank = map { $rank[$_] => $_ } ( 0 .. $#rank );

my @pile_sorted = map { $_->[0] } sort {
         $ord_suit{ $a->[1][1] } <=> $ord_suit{ $b->[1][1] }
      || $ord_rank{ $a->[1][0] } <=> $ord_rank{ $b->[1][0] }
} map { [ $_, [m/(.*)(.)/] ] } @pile;

# Group Cards into Decks
my @deck;
my $lastcard = '';
my $index;

for my $card (@pile_sorted) {
    if ( $card ne $lastcard ) {
        $index = 0;
    }
    else {
        $index++;
    }

    push @{ $deck[$index] }, $card;

    $lastcard = $card;
}

print "Decks\n";
foreach (@deck) {
    print "\t@$_\n";
}

[download]
- Miller

In reply to Re: 52 Perl Pickup by wind
in thread 52 Perl Pickup by dogz007

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