use List::Util 'shuffle';

my @A = (shuffle 0 .. 5)[0 .. 3];
my @B = (shuffle 0 .. 5)[0 .. 3];

my $exact = grep { $A[$_] == $B[$_] } 0 .. 3;

my %in_A    = map { $_ => 1 } @A;
my $inexact = (grep { $in_A{$_} } @B) - $exact;

print "A = [@A]\nB = [@B]\n";
print "exact:   $exact\n";
print "inexact: $inexact\n";