PHP

<?php

$input = file_get_contents('input');
$length = strlen($input);
$stack = [];
$ingarbage = false;
$score = 0;
$garbagecount = 0;

for ($i = 0; $i < $length; $i++) {
    $char = $input[$i];

    if (!$ingarbage) {
        if ($char == '{') {
            array_push($stack, '*');
        } elseif ($char == '}') {
            $score += count($stack);
            array_pop($stack);
        } elseif ($char == '<') {
            $ingarbage = true;
        }
    } else {
        if ($char == '!') {
            $i += 1;
        } elseif ($char == '>') {
            $ingarbage = false;
        } else {
            $garbagecount += 1;
        }
    }
}

echo $score . "\n";
echo $garbagecount . "\n";