use strict;
use warnings;

my $before = [qw(1 2 3 4 5 6 7 8 9 10)];
my $after  = [qw(1 2 3 4 6 7 5 8 9 10)];

# Find the first and last that are out of position
my ($lo_1, $hi_1);
for (0..$#$before) {
  if ($before->[$_] != $after->[$_]) {
    (defined $lo_1 ? $hi_1 : $lo_1) = $_;
  }
}

# If the first item is out of order relative to the one following it,
# it has been moved from higher up; otherwise, the move was in the oth
+er direction
if ($after->[$lo_1+1] < $after->[$lo_1]) {
  print "Moved element $hi_1 to $lo_1\n";
}
else {
  print "Moved element $lo_1 to $hi_1\n";
}
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