AoC 2022, day 10 (perl)

#!/usr/bin/perl

use v5.12;
use warnings;

my $regX  = 1;
my @event = (0);
my $time  = 0;

my $part1 = 0;
my $display;

my @input = <>;

while ($_ = shift @input) {
    if (m#^addx (.*)#) {
        push( @event, $1 );
        unshift( @input, "noop" );
    } else { # noop
        push( @event, 0 );
    }

    $display .= (abs($regX - $time % 40) <= 1) ? '#' : ' ';

    $part1 += $time * $regX  if (++$time % 40 == 20);
    $regX  += shift @event;
}

say "Part 1: $part1";

say "Part 2:";
say substr($display, 0, 40, '')  while( $display );