use strict;
use warnings;

my %cnt;

# Generate all possibilities:
for my $a1 (0 .. 9) {
    for my $a2 (0 .. 9) {
        for my $a3 (0 .. 9) {
            for my $a4 (0 .. 9) {
                my @c = sort ($a1, $a2, $a3, $a4);
                my $s = toStr(@c);
                $cnt{$s}++;
            }
        }
    }
}

my $ttl = 0;
print <<EOHDR;
  num   pct     ttl ttl pct offsets to print
----- ------- ----- ------- ----------------
EOHDR

for my $k (sort { $cnt{$b} <=> $cnt{$a} } keys %cnt) {
    $ttl += $cnt{$k};
    printf "%5u %6.2f  %5u %6.2f  <%s>\n",
        $cnt{$k}, 100*$cnt{$k}/10000.0,
        $ttl,     100*$ttl/10000.0,
        $k;
}

sub toStr {
    my @c = @_;
    my @rv = ();

    for (my $i=1; $i < @c; $i++) {
        if ($c[$i] != $c[$i-1] && $c[$i] != $c[$i-1]+1) {
            push @rv, $c[$i];
        }
    }
    return join(":",@rv);
}