use strict;
use warnings;

my @array = qw(toad frog frig frag crow creep hop);
my @sorted;

for (@array) {
    if ( $_ =~ m/.*r/g ) {
        push( @sorted, $_ );
    }
}
print "$_\n" for sort(@sorted);

##</code><code>##

creep
crow
frag
frig
frog