my @array;
push @{@array},["1", "1", "3"];
push @{@array},["1", "5", "6"];
push @{@array},["1", "1", "3"];

my @unique = ();
my %seen = ();

foreach my $elem ( @array) {

        next if $seen{ $elem }++;
        push @unique, $elem;

}

for my $i (0 .. $#unique) {
        print "\n$unique[$i][0] $unique[$i][1] $unique[$i][2]";
}
print "\n";