use strict;
use warnings;
use feature qw(say);


sub fairShuffle {
    my %count;
    ++$count{$_} for @_;
    my @result;
    for my $key (sort { $count{$a} <=> $count{$b} } keys %count) {
        my $newLength = @result + $count{$key};
        for (1..$count{$key}) {
            splice @result, (($_-1) * $newLength / $count{$key}), 0, $key;
        }
    }
    return @result;
}


my @result = fairShuffle(('a') x 5, ('b') x 3, ('c') x 10, ('d') x 1, ('e') x 1);
say "@result";