Added Devel::Timer, because I'm curious

✗ time perl day7_part2.pl < day7.txt
Move to 464, which will cost you 98363777

Devel::Timer Report -- Total time: 0.3363 secs
Interval  Time    Percent
----------------------------------------------
01 -> 02  0.3356  99.81%  input parsing complete -> solution found
00 -> 01  0.0006   0.19%  INIT -> input parsing complete
perl day7_part2.pl < day7.txt  0.35s user 0.01s system 99% cpu 0.361 total

2021/day7_part2.pl

@@ -1,7 +1,9 @@
 use Modern::Perl;
 use ARGV::OrDATA;
 use List::Util qw(sum);
+use Devel::Timer;
 
+my $t = Devel::Timer->new();
 my %pos;   # count of crabs at each position
 while (<>) {
   chomp;
@@ -13,14 +15,17 @@
 my @all_pos = sort { $a <=> $b } keys %pos;
 my $min = $all_pos[0];
 my $max = $all_pos[-1];
+$t->mark('input parsing complete');
+
 my %all_costs;
 foreach my $x ($min..$max) {
   my $cost = cost_to_move_to($x);
   $all_costs{$cost} = $x;
 }
 my ($min_cost) = sort { $a <=> $b } keys %all_costs;
 say "Move to $all_costs{$min_cost}, which will cost you $min_cost";
-
+$t->mark('solution found');
+$t->report;
 
 sub cost_to_move_to {
   (my $x) = @_;