use strict;
my @original = qw/1 3 2 4/;
my @kopie = qw/3 2 1 4 2 3 2 1 4/;
for my $v (0..$#original) {
  print "$v ($original[$v]) Element: ",
  join(" & ",grep($original[$v]==$kopie[$_],(0..$#kopie))),"\n";
}
_ _ END _ _
0 (1) Element: 2 & 7
1 (3) Element: 0 & 5
2 (2) Element: 1 & 4 & 6
3 (4) Element: 3 & 8