my @elems = ("x", "y", "z");
# array size may be varied (lesser or more than 3)
my @tobepopulated = ("foo", "foo", "foo", "foo", "foo", "foo", "foo", +"foo", "foo", "foo");
# this can be more 10 elements 

my $m= 2 * scalar @tobepopulated;
my $d= 2 * scalar @elems;
die "too few elements to be populated" unless $m >= $d;

my $i= 0;
my $n= $d/2;

foreach (@tobepopulated) {
	$_.= '-' . $elems[$i];
	$n+= $d;
	if ( $n > $m ) {
		$n-= $m;
		++$i;
	}
}
print join "\n",@tobepopulated,'';