#! perl -slw
use strict;
use Data::Dump qw[ pp ];
use Algorithm::Combinatorics qw[ variations_with_repetition ];

our $N //= 4;

my @perms = map join( '', @$_ ), variations_with_repetition( [ 1 .. $N ], $N );

my %lookup;
$lookup{ $perms[ $_ ] } = $_ for 0 .. $#perms;

my @counts = (0) x @perms;

for( 1 .. 1e3 ) {
    my $observed = join '', map 1+int( rand $N ), 1 .. $N; ## random observation
    ++$counts[ $lookup{ $observed } ];
}

printf "%${N}s : %${N}d\n", $perms[ $_ ], $counts[ $_ ]
    for 0 .. $#perms;