@union = ((SDT,`1781183799.44927\',-----),
(BN,`1781183799.44972\',-----),
(BNN,`1781183799.46753\',-----));

@ICUNAV = ((BN,`1781183799.44972\',-----),
(BNN,`1781183799.46753\',-----),(SFG,`1781183799.46753\',-----));

##</code><code>##

@diff =
((SDT,`1781183799.44927\',-----),
(SFG,`1781183799.46753\',-----));

##</code><code>##

my @diff;
my @inter;

my %count2 = ();
foreach my $element (@union,@ICUNAV) 
{
$count2{$element}++;
};
foreach my $element (keys %count2) 
{
push @{ $count2{$element} > 1 ? \@inter : \@diff }, $element;
};
print Dumper(@diff),"\n";